World Wide Web
Encyclopedia
The World Wide Web (or the proper World-Wide Web; abbreviated as WWW or W3, and commonly known as the Web) is a system
of interlinked hypertext
documents accessed via the Internet
. With a web browser
, one can view web page
s that may contain text, images, videos, and other multimedia
and navigate
between them via hyperlink
s.
Using concepts from earlier hypertext systems, British engineer and computer scientist
Sir Tim Berners-Lee
, now Director of the World Wide Web Consortium
(W3C), wrote a proposal in March 1989 for what would eventually become the World Wide Web. At CERN
in Geneva, Switzerland, Berners-Lee and Belgian computer scientist Robert Cailliau
proposed in 1990 to use hypertext "... to link and access information of various kinds as a web of nodes in which the user can browse at will", and they publicly introduced the project in December.
"The World-Wide Web was developed to be a pool of human knowledge, and human culture, which would allow collaborators in remote sites to share their ideas and all aspects of a common project."
was reported to have predicted that satellites would one day "bring the accumulated knowledge of the world to your fingertips" using a console that would combine the functionality of the Xerox, telephone, television and a small computer, allowing data transfer and video conferencing around the globe.
In March 1989, Tim Berners-Lee wrote a proposal that referenced ENQUIRE
, a database and software project he had built in 1980, and described a more elaborate information management system.
With help from Robert Cailliau
, he published a more formal proposal (on November 12, 1990) to build a "Hypertext project" called "WorldWideWeb" (one word, also "W3") as a "web" of "hypertext documents" to be viewed by "browsers
" using a client–server architecture. This proposal estimated that a read-only web would be developed within three months and that it would take six months to achieve "the creation of new links and new material by readers, [so that] authorship becomes universal" as well as "the automatic notification of a reader when new material of interest to him/her has become available." While the read-only goal was met, accessible authorship of web content took longer to mature, with the wiki
concept, blog
s, Web 2.0
and RSS
/Atom
.
The proposal was modeled after the Dynatext
SGML reader by Electronic Book Technology, a spin-off from the Institute for Research in Information and Scholarship at Brown University. The Dynatext system, licensed by CERN, was technically advanced and was a key player in the extension of SGML ISO 8879:1986 to Hypermedia within HyTime
, but it was considered too expensive and had an inappropriate licensing policy for use in the general high energy physics community, namely a fee for each document and each document alteration.
A NeXT Computer
was used by Berners-Lee as the world's first web server
and also to write the first web browser
, WorldWideWeb
, in 1990. By Christmas 1990, Berners-Lee had built all the tools necessary for a working Web: the first web browser
(which was a web editor as well); the first web server; and the first web pages, which described the project itself. On August 6, 1991, he posted a short summary of the World Wide Web project on the alt.hypertext newsgroup
. This date also marked the debut of the Web as a publicly available service on the Internet. The first photo on the web was uploaded by Berners-Lee in 1992, an image of the CERN house band Les Horribles Cernettes
.
The first server outside Europe was set up at SLAC to host the SPIRES-HEP
database. Accounts differ substantially as to the date of this event. The World Wide Web Consortium says December 1992, whereas SLAC itself claims 1991. This is supported by a W3C document entitled A Little History of the World Wide Web.
The crucial underlying concept of hypertext
originated with older projects from the 1960s, such as the Hypertext Editing System (HES) at Brown University, Ted Nelson
's Project Xanadu
, and Douglas Engelbart
's oN-Line System
(NLS). Both Nelson and Engelbart were in turn inspired by Vannevar Bush
's microfilm-based "memex
", which was described in the 1945 essay "As We May Think
".
Berners-Lee's breakthrough was to marry hypertext to the Internet. In his book Weaving The Web
, he explains that he had repeatedly suggested that a marriage between the two technologies was possible to members of both technical communities, but when no one took up his invitation, he finally tackled the project himself. In the process, he developed three essential technologies:
The World Wide Web had a number of differences from other hypertext systems that were then available. The Web required only unidirectional links rather than bidirectional ones. This made it possible for someone to link to another resource without action by the owner of that resource. It also significantly reduced the difficulty of implementing web servers and browsers (in comparison to earlier systems), but in turn presented the chronic problem of link rot
. Unlike predecessors such as HyperCard
, the World Wide Web was non-proprietary, making it possible to develop servers and clients independently and to add extensions without licensing restrictions. On April 30, 1993, CERN announced that the World Wide Web would be free to anyone, with no fees due. Coming two months after the announcement that the server implementation of the Gopher protocol was no longer free to use, this produced a rapid shift away from Gopher and towards the Web. An early popular web browser was ViolaWWW
for Unix
and the X Windowing System.
Scholars generally agree that a turning point for the World Wide Web began with the introduction of the Mosaic
web browser in 1993. A graphical browser developed by a team at the National Center for Supercomputing Applications
at the University of Illinois at Urbana-Champaign
(NCSA-UIUC), led by Marc Andreessen
, funding for Mosaic came from the U.S. High-Performance Computing and Communications Initiative and the High Performance Computing and Communication Act of 1991
, one of several computing developments initiated by U.S. Senator Al Gore
. Prior to the release of Mosaic, graphics were not commonly mixed with text in web pages and the Web's popularity was less than older protocols in use over the Internet, such as Gopher and Wide Area Information Servers (WAIS). Mosaic's graphical user interface allowed the Web to become, by far, the most popular Internet protocol.
The World Wide Web Consortium
(W3C) was founded by Tim Berners-Lee after he left the European Organization for Nuclear Research (CERN) in October 1994. It was founded at the Massachusetts Institute of Technology
Laboratory for Computer Science (MIT/LCS) with support from the Defense Advanced Research Projects Agency
(DARPA), which had pioneered the Internet; a year later, a second site was founded at INRIA (a French national computer research lab) with support from the European Commission
DG InfSo; and in 1996, a third continental site was created in Japan at Keio University. By the end of 1994, while the total number of websites was still minute compared to present standards, quite a number of notable websites were already active, many of which are the precursors or inspiration for today's most popular services.
Connected by the existing Internet, other websites were created around the world, adding international standards for domain name
s and HTML
. Since then, Berners-Lee has played an active role in guiding the development of web standards (such as the markup language
s in which web pages are composed), and in recent years has advocated his vision of a Semantic Web
. The World Wide Web enabled the spread of information over the Internet through an easy-to-use and flexible format. It thus played an important role in popularizing use of the Internet. Although the two terms are sometimes conflated
in popular use, World Wide Web is not synonym
ous with Internet. The Web is a collection of documents and both client and server software using Internet protocols such as TCP/IP and HTTP.
"running" on the Internet.
Viewing a web page
on the World Wide Web normally begins either by typing the URL
of the page into a web browser
or by following a hyperlink
to that page or resource. The web browser then initiates a series of communication messages, behind the scenes, in order to fetch and display it. As an example, consider the Wikipedia page for this article with the URLhttp://en.wikipedia.org/wiki/World_Wide_Web .
First, the browser resolves the server-name portion of the URL (en.wikipedia.org) into an Internet Protocol address
using the globally distributed database known as the Domain Name System
(DNS); this lookup returns an IP address such as 208.80.152.2. The browser then requests the resource by sending an HTTP
request across the Internet to the computer at that particular address. It makes the request to a particular application port in the underlying Internet Protocol Suite
so that the computer receiving the request can distinguish an HTTP request from other network protocols it may be servicing such as e-mail delivery; the HTTP protocol normally uses port 80. The content of the HTTP request can be as simple as the two lines of text
GET /wiki/World_Wide_Web HTTP/1.1
Host: en.wikipedia.org
The computer receiving the HTTP request delivers it to Web server
software listening for requests on port 80. If the web server can fulfill the request it sends an HTTP response back to the browser indicating success, which can be as simple as
HTTP/1.0 200 OK
Content-Type: text/html; charset=UTF-8
followed by the content of the requested page. The Hypertext Markup Language for a basic web page looks like
World Wide Web — Wikipedia, the free encyclopedia
The web browser parses
the HTML, interpreting the markup ( , for bold, and such) that surrounds the words in order to draw that text on the screen.
Many web pages consist of more elaborate HTML which references the URLs of other resources such as images, other embedded media, scripts
that affect page behavior, and Cascading Style Sheets
that affect page layout. A browser that handles complex HTML will make additional HTTP requests to the web server for these other Internet media type
s. As it receives their content from the web server, the browser progressively renders
the page onto the screen as specified by its HTML and these additional resources.
Early archive
of the first Web site
Such a collection of useful, related resources, interconnected via hypertext links is dubbed a web of information. Publication on the Internet created what Tim Berners-Lee
first called the WorldWideWeb (in its original CamelCase
, which was subsequently discarded) in November 1990.
The hyperlink structure of the WWW is described by the webgraph
: the nodes of the webgraph
correspond to the web pages (or URLs) the directed edges between them to the hyperlink
s.
Over time, many web resources pointed to by hyperlinks disappear, relocate, or are replaced with different content. This makes hyperlinks obsolete, a phenomenon referred to in some circles as link rot
and the hyperlinks affected by it are often called dead links. The ephemeral nature of the Web has prompted many efforts to archive web sites. The Internet Archive
, active since 1996, is one of the best-known efforts.
is a scripting language that was initially developed in 1995 by Brendan Eich
, then of Netscape
, for use within web pages. The standardized version is ECMAScript
. To overcome some of the limitations of the page-by-page model described above, some web applications also use Ajax
(asynchronous
JavaScript and XML
). JavaScript is delivered with the page that can make additional HTTP requests to the server, either in response to user actions such as mouse-clicks or based on lapsed time. The server's responses are used to modify the current page rather than creating a new page with each response. Thus, the server must provide only limited, incremental information. Since multiple Ajax requests can be handled at the same time, users can interact with a page even while data is being retrieved. Some web applications regularly poll
the server to ask whether new information is available.
for a web server
is often www, in the same way that it may be ftp for an FTP server, and news or nntp for a USENET
news server
. These host names appear as Domain Name System
(DNS) subdomain
names, as in www.example.com. The use of 'www' as a subdomain name is not required by any technical or policy standard; indeed, the first ever web server was called nxoc01.cern.ch, and many web sites exist without it. Many established websites still use 'www', or they invent other subdomain names such as 'www2', 'secure', etc. Many such web servers are set up such that both the domain root (e.g., example.com) and the www subdomain (e.g., www.example.com) refer to the same site; others require one form or the other, or they may map to different web sites.
The use of a subdomain name is useful for load balancing
incoming web traffic by creating a CNAME record
that points to a cluster of web servers. Since, currently, only a subdomain can be cname'ed, the same result cannot be achieved by using the bare domain root.
When a user submits an incomplete domain name to a web browser in its address bar input field, some web browsers automatically try adding the prefix "www" to the beginning of it and possibly ".com", ".org" and ".net" at the end, depending on what might be missing. For example, entering '' may be transformed tohttp://www.microsoft.com/ and 'openoffice' to http://www.openoffice.org . This feature started appearing in early versions of Mozilla Firefox, when it still had the working title 'Firebird' in early 2003, from an earlier practice in browsers such as Lynx
. It is reported that Microsoft was granted a US patent for the same idea in 2008, but only for mobile devices.
In English, www is pronounced by individually pronouncing the name of characters (double-u double-u double-u) or by saying the phrase "triple double-u". Although some technical users pronounce it dub-dub-dub, this is not widespread. The English writer Douglas Adams
once quipped in The Independent on Sunday
(1999): "The World Wide Web is the only thing I know of whose shortened form takes three times longer to say than what it's short for," with Stephen Fry later pronouncing it in his "Podgrammes" series of podcasts as "wuh wuh wuh." In Mandarin Chinese, World Wide Web is commonly translated via a phono-semantic matching
to wàn wéi wǎng , which satisfies www and literally means "myriad dimensional net", a translation that very appropriately reflects the design concept and proliferation of the World Wide Web. Tim Berners-Lee's web-space states that World Wide Web is officially spelled as three separate words, each capitalized, with no intervening hyphens.
Use of the www prefix is declining as Web 2.0
web application
s seek to brand
their domain names and make them easily pronounceable. As the mobile web
grows in popularity, services like Gmail.com, MySpace
.com, Facebook
.com and Twitter
.com are most often discussed without adding the www to the domain (or the .com)
http:// or https:// ) in URIs
refer to the Hypertext Transfer Protocol
and to HTTP Secure, respectively, and so define the communication protocol to be used for the request and response. The HTTP protocol is fundamental to the operation of the World Wide Web; the added encryption layer in HTTPS is essential when confidential information such as passwords or banking information are to be exchanged over the public Internet. Web browsers usually prepend the scheme to URLs too, if omitted.
, and of the generations of people within the United States who have had access to the internet from a young age, half have some form of Social Networking presence. and are part of a generational shift that could be changing norms. The social network Facebook progressed from U.S. college students to a 70% non-U.S. audience, but in 2009 estimated that only 20% of its members use privacy settings. In 2010 (six years after co-founding the company), Mark Zuckerberg
wrote, "we will add privacy controls that are much simpler to use".
Privacy representatives from 60 countries have resolved to ask for laws to complement industry self-regulation, for education for children and other minors who use the Web, and for default protections for users of social networks. They also believe data protection for personally identifiable information
benefits business more than the sale of that information. Users can opt-in to features in browsers to clear their personal histories locally and block some cookies
and advertising network
s but they are still tracked in websites' server log
s, and in particular web beacons. Berners-Lee and colleagues see hope in accountability and appropriate use achieved by extending the Web's architecture to policy awareness, perhaps with audit logging, reasoners and appliances.
In exchange for providing free content, vendors hire advertisers who spy on Web users and base their business model on tracking them. Since 2009, they buy and sell consumer data on exchanges (lacking a few details that could make it possible to de-anonymize, or identify an individual). Hundreds of millions of times per day, Lotame Solutions captures what users are typing in real time, and sends that text to OpenAmplify who then tries to determine, to quote a writer at The Wall Street Journal
, "what topics are being discussed, how the author feels about those topics, and what the person is going to do about them".
Microsoft
backed away in 2008 from its plans for strong privacy features in Internet Explorer, leaving its users (50% of the world's Web users) open to advertisers who may make assumptions about them based on only one click when they visit a website. Among services paid for by advertising, Yahoo!
could collect the most data about users of commercial websites, about 2,500 bits of information per month about each typical user of its site and its affiliated advertising network sites. Yahoo! was followed by MySpace with about half that potential and then by AOL
–TimeWarner, Google
, Facebook, Microsoft, and eBay
.
. Cybercrime carried out on the Web can include identity theft
, fraud
, espionage and intelligence gathering. Web-based vulnerabilities
now outnumber traditional computer security concerns, and as measured by Google
, about one in ten web pages may contain malicious code. Most Web-based attacks
take place on legitimate websites, and most, as measured by Sophos
, are hosted in the United States, China and Russia. The most common of all malware threats
is SQL injection
attacks against websites. Through HTML and URIs the Web was vulnerable to attacks like cross-site scripting
(XSS) that came with the introduction of JavaScript and were exacerbated to some degree by Web 2.0 and Ajax web design
that favors the use of scripts. Today by one estimate, 70% of all websites are open to XSS attacks on their users.
Proposed solutions vary to extremes. Large security vendors like McAfee
already design governance and compliance suites to meet post-9/11 regulations, and some, like Finjan
have recommended active real-time inspection of code and all content regardless of its source. Some have argued that for enterprise to see security as a business opportunity rather than a cost center, "ubiquitous, always-on digital rights management" enforced in the infrastructure by a handful of organizations must replace the hundreds of companies that today secure data and networks. Jonathan Zittrain
has said users sharing responsibility for computing safety is far preferable to locking down the Internet.
(IETF) and other organizations.
Usually, when web standards are discussed, the following publications are seen as foundational:
Additional publications provide definitions of other essential technologies for the World Wide Web, including, but not limited to, the following:
to people with disabilities. Tim Berners-Lee once noted, "The power of the Web is in its universality. Access by everyone regardless of disability is an essential aspect." Many countries regulate web accessibility
as a requirement for websites. International cooperation in the W3C Web Accessibility Initiative
led to simple guidelines that web content authors as well as software developers can use to make the Web accessible to persons who may or may not be using assistive technology
.
Activity assures that web technology will work in all languages, scripts, and cultures. Beginning in 2004 or 2005, Unicode
gained ground and eventually in December 2007 surpassed both ASCII
and Western European as the Web's most frequently used character encoding
. Originally RFC 3986 allowed resources to be identified by URI
in a subset of US-ASCII. RFC 3987 allows more characters—any character in the Universal Character Set
—and now a resource can be identified by IRI
in any language.
. A 2002 survey of 2,024 million Web pages determined that by far the most Web content was in English: 56.4%; next were pages in German (7.7%), French (5.6%), and Japanese (4.9%). A more recent study, which used Web searches in 75 different languages to sample the Web, determined that there were over 11.5 billion Web pages in the publicly indexable Web
as of the end of January 2005. , the indexable web contains at least 25.21 billion pages. On July 25, 2008, Google software engineers Jesse Alpert and Nissan Hajaj announced that Google Search
had discovered one trillion unique URLs. , over 109.5 million domains operated. Of these 74% were commercial or other sites operating in the
.
Statistics measuring a website's popularity are usually based either on the number of page view
s or on associated server 'hits
' (file requests) that it receives.
issues in the Internet infrastructure and the high latency
that results in slow browsing has led to a pejorative name for the World Wide Web: the World Wide Wait. Speeding up the Internet is an ongoing discussion over the use of peering
and QoS
technologies. Other solutions to reduce the congestion can be found at W3C. Guideline
s for Web response times are:
recently obtained data, usually on the local hard drive. HTTP requests sent by a browser will usually ask only for data that has changed since the last download. If the locally cached data are still current, it will be reused. Caching helps reduce the amount of Web traffic on the Internet. The decision about expiration is made independently for each downloaded file, whether image, stylesheet
, JavaScript
, HTML, or whatever other content the site may provide. Thus even on sites with highly dynamic content, many of the basic resources need to be refreshed only occasionally. Web site designers find it worthwhile to collate resources such as CSS data and JavaScript into a few site-wide files so that they can be cached efficiently. This helps reduce page download times and lowers demands on the Web server.
There are other components of the Internet that can cache Web content. Corporate and academic firewalls often cache Web resources requested by one user for the benefit of all. (See also Caching proxy server.) Some search engines also store cached content from websites. Apart from the facilities built into Web servers that can determine when files have been updated and so need to be re-sent, designers of dynamically generated Web pages can control the HTTP headers sent back to requesting users, so that transient or sensitive pages are not cached. Internet banking
and news sites frequently use this facility. Data requested with an HTTP
'GET' is likely to be cached if other conditions are met; data obtained in response to a 'POST' is assumed to depend on the data that was POSTed and so is not cached.
Information system
An information system - or application landscape - is any combination of information technology and people's activities that support operations, management, and decision making. In a very broad sense, the term information system is frequently used to refer to the interaction between people,...
of interlinked hypertext
Hypertext
Hypertext is text displayed on a computer or other electronic device with references to other text that the reader can immediately access, usually by a mouse click or keypress sequence. Apart from running text, hypertext may contain tables, images and other presentational devices. Hypertext is the...
documents accessed via the Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
. With a web browser
Web browser
A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...
, one can view web page
Web page
A web page or webpage is a document or information resource that is suitable for the World Wide Web and can be accessed through a web browser and displayed on a monitor or mobile device. This information is usually in HTML or XHTML format, and may provide navigation to other web pages via hypertext...
s that may contain text, images, videos, and other multimedia
Multimedia
Multimedia is media and content that uses a combination of different content forms. The term can be used as a noun or as an adjective describing a medium as having multiple content forms. The term is used in contrast to media which use only rudimentary computer display such as text-only, or...
and navigate
Web navigation
- A central theme in web design is the development of a web navigation interface that maximizes usability.- - - -See also:- Design pattern - - Efficiency- - Human–computer interaction- - Interaction technique- -...
between them via hyperlink
Hyperlink
In computing, a hyperlink is a reference to data that the reader can directly follow, or that is followed automatically. A hyperlink points to a whole document or to a specific element within a document. Hypertext is text with hyperlinks...
s.
Using concepts from earlier hypertext systems, British engineer and computer scientist
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...
Sir Tim Berners-Lee
Tim Berners-Lee
Sir Timothy John "Tim" Berners-Lee, , also known as "TimBL", is a British computer scientist, MIT professor and the inventor of the World Wide Web...
, now Director of the World Wide Web Consortium
World Wide Web Consortium
The World Wide Web Consortium is the main international standards organization for the World Wide Web .Founded and headed by Tim Berners-Lee, the consortium is made up of member organizations which maintain full-time staff for the purpose of working together in the development of standards for the...
(W3C), wrote a proposal in March 1989 for what would eventually become the World Wide Web. At CERN
CERN
The European Organization for Nuclear Research , known as CERN , is an international organization whose purpose is to operate the world's largest particle physics laboratory, which is situated in the northwest suburbs of Geneva on the Franco–Swiss border...
in Geneva, Switzerland, Berners-Lee and Belgian computer scientist Robert Cailliau
Robert Cailliau
Robert Cailliau , born 26 January 1947, is a Belgian informatics engineer and computer scientist who, together with Sir Tim Berners-Lee, developed the World Wide Web.-Biography:...
proposed in 1990 to use hypertext "... to link and access information of various kinds as a web of nodes in which the user can browse at will", and they publicly introduced the project in December.
"The World-Wide Web was developed to be a pool of human knowledge, and human culture, which would allow collaborators in remote sites to share their ideas and all aspects of a common project."
History
In the June 1970 issue of Popular Science magazine Arthur C. ClarkeArthur C. Clarke
Sir Arthur Charles Clarke, CBE, FRAS was a British science fiction author, inventor, and futurist, famous for his short stories and novels, among them 2001: A Space Odyssey, and as a host and commentator in the British television series Mysterious World. For many years, Robert A. Heinlein,...
was reported to have predicted that satellites would one day "bring the accumulated knowledge of the world to your fingertips" using a console that would combine the functionality of the Xerox, telephone, television and a small computer, allowing data transfer and video conferencing around the globe.
In March 1989, Tim Berners-Lee wrote a proposal that referenced ENQUIRE
ENQUIRE
ENQUIRE was an early software project written in 1980 by Tim Berners-Lee at CERN, which was the predecessor to the World Wide Web in 1989.It was a simple hypertext program that had some of the same ideas as the Web and the Semantic Web but was different in several important ways.According to...
, a database and software project he had built in 1980, and described a more elaborate information management system.
With help from Robert Cailliau
Robert Cailliau
Robert Cailliau , born 26 January 1947, is a Belgian informatics engineer and computer scientist who, together with Sir Tim Berners-Lee, developed the World Wide Web.-Biography:...
, he published a more formal proposal (on November 12, 1990) to build a "Hypertext project" called "WorldWideWeb" (one word, also "W3") as a "web" of "hypertext documents" to be viewed by "browsers
Web browser
A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...
" using a client–server architecture. This proposal estimated that a read-only web would be developed within three months and that it would take six months to achieve "the creation of new links and new material by readers, [so that] authorship becomes universal" as well as "the automatic notification of a reader when new material of interest to him/her has become available." While the read-only goal was met, accessible authorship of web content took longer to mature, with the wiki
Wiki
A wiki is a website that allows the creation and editing of any number of interlinked web pages via a web browser using a simplified markup language or a WYSIWYG text editor. Wikis are typically powered by wiki software and are often used collaboratively by multiple users. Examples include...
concept, blog
Blog
A blog is a type of website or part of a website supposed to be updated with new content from time to time. Blogs are usually maintained by an individual with regular entries of commentary, descriptions of events, or other material such as graphics or video. Entries are commonly displayed in...
s, Web 2.0
Web 2.0
The term Web 2.0 is associated with web applications that facilitate participatory information sharing, interoperability, user-centered design, and collaboration on the World Wide Web...
and RSS
RSS
-Mathematics:* Root-sum-square, the square root of the sum of the squares of the elements of a data set* Residual sum of squares in statistics-Technology:* RSS , "Really Simple Syndication" or "Rich Site Summary", a family of web feed formats...
/Atom
Atom (standard)
The name Atom applies to a pair of related standards. The Atom Syndication Format is an XML language used for web feeds, while the Atom Publishing Protocol is a simple HTTP-based protocol for creating and updating web resources.Web feeds allow software programs to check for updates published on a...
.
The proposal was modeled after the Dynatext
Dynatext
DynaText is an SGML publishing tool. It was introduced in 1990, and was the first system to handle arbitrarily large SGML documents, and to render them according to multiple style-sheets that could be switched at will....
SGML reader by Electronic Book Technology, a spin-off from the Institute for Research in Information and Scholarship at Brown University. The Dynatext system, licensed by CERN, was technically advanced and was a key player in the extension of SGML ISO 8879:1986 to Hypermedia within HyTime
HyTime
HyTime is a markup language that is an "application" of SGML. HyTime defines a set of hypertext-oriented element types that, in effect, supplement SGML and allow SGML document authors to build hypertext and multimedia presentations in a standardized way.HyTime is an international standard...
, but it was considered too expensive and had an inappropriate licensing policy for use in the general high energy physics community, namely a fee for each document and each document alteration.
A NeXT Computer
NeXT Computer
The NeXT Computer was a high-end workstation computer developed, manufactured and sold by Steve Jobs' company NeXT from 1988 until 1990. It ran the Unix-based NeXTSTEP operating system. The NeXT Computer was packaged in a 1-foot die-cast magnesium cube-shaped case, which led to the machine being...
was used by Berners-Lee as the world's first web server
Web server
Web server can refer to either the hardware or the software that helps to deliver content that can be accessed through the Internet....
and also to write the first web browser
Web browser
A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...
, WorldWideWeb
WorldWideWeb
WorldWideWeb, later renamed to Nexus to avoid confusion between the software and the World Wide Web, was the first web browser and editor. When it was written, WorldWideWeb was the only way to view the Web....
, in 1990. By Christmas 1990, Berners-Lee had built all the tools necessary for a working Web: the first web browser
WorldWideWeb
WorldWideWeb, later renamed to Nexus to avoid confusion between the software and the World Wide Web, was the first web browser and editor. When it was written, WorldWideWeb was the only way to view the Web....
(which was a web editor as well); the first web server; and the first web pages, which described the project itself. On August 6, 1991, he posted a short summary of the World Wide Web project on the alt.hypertext newsgroup
Newsgroup
A usenet newsgroup is a repository usually within the Usenet system, for messages posted from many users in different locations. The term may be confusing to some, because it is usually a discussion group. Newsgroups are technically distinct from, but functionally similar to, discussion forums on...
. This date also marked the debut of the Web as a publicly available service on the Internet. The first photo on the web was uploaded by Berners-Lee in 1992, an image of the CERN house band Les Horribles Cernettes
Les Horribles Cernettes
Les Horribles Cernettes is an all-female parody pop group, self-labelled "the one and only High Energy Rock Band", founded by employees of CERN which performs at CERN and other HEP related events. Their musical style is often described as doo-wop...
.
The first server outside Europe was set up at SLAC to host the SPIRES-HEP
Spires
Spires may refer to:* SPIRES, a database for publications in High-Energy Physics* Speyer , a city in Germany* The Spires, a commercial conference centre, operated out of Church House, Belfast by the Presbyterian Church in Ireland...
database. Accounts differ substantially as to the date of this event. The World Wide Web Consortium says December 1992, whereas SLAC itself claims 1991. This is supported by a W3C document entitled A Little History of the World Wide Web.
The crucial underlying concept of hypertext
Hypertext
Hypertext is text displayed on a computer or other electronic device with references to other text that the reader can immediately access, usually by a mouse click or keypress sequence. Apart from running text, hypertext may contain tables, images and other presentational devices. Hypertext is the...
originated with older projects from the 1960s, such as the Hypertext Editing System (HES) at Brown University, Ted Nelson
Ted Nelson
Theodor Holm Nelson is an American sociologist, philosopher, and pioneer of information technology. He coined the terms "hypertext" and "hypermedia" in 1963 and published it in 1965...
's Project Xanadu
Project Xanadu
Project Xanadu was the first hypertext project, founded in 1960 by Ted Nelson. Administrators of Project Xanadu have declared it an improvement over the World Wide Web, with mission statement: "Today's popular software simulates paper...
, and Douglas Engelbart
Douglas Engelbart
Douglas Carl Engelbart is an American inventor, and an early computer and internet pioneer. He is best known for his work on the challenges of human-computer interaction, resulting in the invention of the computer mouse, and the development of hypertext, networked computers, and precursors to GUIs...
's oN-Line System
NLS (computer system)
NLS, or the "oN-Line System", was a revolutionary computer collaboration system designed by Douglas Engelbart and implemented by researchers at the Augmentation Research Center at the Stanford Research Institute during the 1960s...
(NLS). Both Nelson and Engelbart were in turn inspired by Vannevar Bush
Vannevar Bush
Vannevar Bush was an American engineer and science administrator known for his work on analog computing, his political role in the development of the atomic bomb as a primary organizer of the Manhattan Project, the founding of Raytheon, and the idea of the memex, an adjustable microfilm viewer...
's microfilm-based "memex
Memex
The memex is the name given by Vannevar Bush to the hypothetical proto-hypertext system he described in his 1945 The Atlantic Monthly article As We May Think...
", which was described in the 1945 essay "As We May Think
As We May Think
As We May Think is an essay by Vannevar Bush, first published in The Atlantic Monthly in July 1945, and republished again as an abridged version in September 1945 — before and after the U.S. nuclear attacks on Japan...
".
Berners-Lee's breakthrough was to marry hypertext to the Internet. In his book Weaving The Web
Weaving the Web: The Original Design and Ultimate Destiny of the World Wide Web by its inventor
Weaving the Web: The Original Design and Ultimate Destiny of the World Wide Web by its inventor is a book written by Tim Berners-Lee describing how the world wide web was created and his role in it. It is the only book written by Berners-Lee....
, he explains that he had repeatedly suggested that a marriage between the two technologies was possible to members of both technical communities, but when no one took up his invitation, he finally tackled the project himself. In the process, he developed three essential technologies:
- a system of globally unique identifiers for resources on the Web and elsewhere, the Universal Document Identifier (UDI), later known as Uniform Resource LocatorUniform Resource LocatorIn computing, a uniform resource locator or universal resource locator is a specific character string that constitutes a reference to an Internet resource....
(URL) and Uniform Resource IdentifierUniform Resource IdentifierIn computing, a uniform resource identifier is a string of characters used to identify a name or a resource on the Internet. Such identification enables interaction with representations of the resource over a network using specific protocols...
(URI); - the publishing language HyperText Markup Language (HTML);
- the Hypertext Transfer ProtocolHypertext Transfer ProtocolThe Hypertext Transfer Protocol is a networking protocol for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web....
(HTTP).
The World Wide Web had a number of differences from other hypertext systems that were then available. The Web required only unidirectional links rather than bidirectional ones. This made it possible for someone to link to another resource without action by the owner of that resource. It also significantly reduced the difficulty of implementing web servers and browsers (in comparison to earlier systems), but in turn presented the chronic problem of link rot
Link rot
Link rot , also known as link death or link breaking is an informal term for the process by which, either on individual websites or the Internet in general, increasing numbers of links point to web pages, servers or other resources that have become permanently unavailable...
. Unlike predecessors such as HyperCard
HyperCard
HyperCard is an application program created by Bill Atkinson for Apple Computer, Inc. that was among the first successful hypermedia systems before the World Wide Web. It combines database capabilities with a graphical, flexible, user-modifiable interface. HyperCard also features HyperTalk, written...
, the World Wide Web was non-proprietary, making it possible to develop servers and clients independently and to add extensions without licensing restrictions. On April 30, 1993, CERN announced that the World Wide Web would be free to anyone, with no fees due. Coming two months after the announcement that the server implementation of the Gopher protocol was no longer free to use, this produced a rapid shift away from Gopher and towards the Web. An early popular web browser was ViolaWWW
ViolaWWW
ViolaWWW, first developed in the early 1990s, for Unix and the X Windowing System, was the first popular web browser which, until Mosaic, was the most frequently used web browser for access to the World Wide Web...
for Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
and the X Windowing System.
Scholars generally agree that a turning point for the World Wide Web began with the introduction of the Mosaic
Mosaic (web browser)
Mosaic is the web browser credited with popularizing the World Wide Web. It was also a client for earlier protocols such as FTP, NNTP, and gopher. Its clean, easily understood user interface, reliability, Windows port and simple installation all contributed to making it the application that opened...
web browser in 1993. A graphical browser developed by a team at the National Center for Supercomputing Applications
National Center for Supercomputing Applications
The National Center for Supercomputing Applications is an American state-federal partnership to develop and deploy national-scale cyberinfrastructure that advances science and engineering. NCSA operates as a unit of the University of Illinois at Urbana-Champaign but it provides high-performance...
at the University of Illinois at Urbana-Champaign
University of Illinois at Urbana-Champaign
The University of Illinois at Urbana–Champaign is a large public research-intensive university in the state of Illinois, United States. It is the flagship campus of the University of Illinois system...
(NCSA-UIUC), led by Marc Andreessen
Marc Andreessen
Marc Andreessen is an American entrepreneur, investor, software engineer, and multi-millionaire best known as co-author of Mosaic, the first widely-used web browser, and co-founder of Netscape Communications Corporation. He founded and later sold the software company Opsware to Hewlett-Packard...
, funding for Mosaic came from the U.S. High-Performance Computing and Communications Initiative and the High Performance Computing and Communication Act of 1991
High Performance Computing and Communication Act of 1991
The High Performance Computing and Communication Act of 1991 is an Act of Congress promulgated in the 102nd United States Congress as on 1991-12-09...
, one of several computing developments initiated by U.S. Senator Al Gore
Al Gore and information technology
Al Gore served as the Vice President of the United States from 1993–2001. He is the co-winner of the 2007 Nobel Peace Prize. In the 1990s he promoted legislation that funded an expansion of and greater public access to the internet....
. Prior to the release of Mosaic, graphics were not commonly mixed with text in web pages and the Web's popularity was less than older protocols in use over the Internet, such as Gopher and Wide Area Information Servers (WAIS). Mosaic's graphical user interface allowed the Web to become, by far, the most popular Internet protocol.
The World Wide Web Consortium
World Wide Web Consortium
The World Wide Web Consortium is the main international standards organization for the World Wide Web .Founded and headed by Tim Berners-Lee, the consortium is made up of member organizations which maintain full-time staff for the purpose of working together in the development of standards for the...
(W3C) was founded by Tim Berners-Lee after he left the European Organization for Nuclear Research (CERN) in October 1994. It was founded at the Massachusetts Institute of Technology
Massachusetts Institute of Technology
The Massachusetts Institute of Technology is a private research university located in Cambridge, Massachusetts. MIT has five schools and one college, containing a total of 32 academic departments, with a strong emphasis on scientific and technological education and research.Founded in 1861 in...
Laboratory for Computer Science (MIT/LCS) with support from the Defense Advanced Research Projects Agency
Defense Advanced Research Projects Agency
The Defense Advanced Research Projects Agency is an agency of the United States Department of Defense responsible for the development of new technology for use by the military...
(DARPA), which had pioneered the Internet; a year later, a second site was founded at INRIA (a French national computer research lab) with support from the European Commission
European Commission
The European Commission is the executive body of the European Union. The body is responsible for proposing legislation, implementing decisions, upholding the Union's treaties and the general day-to-day running of the Union....
DG InfSo; and in 1996, a third continental site was created in Japan at Keio University. By the end of 1994, while the total number of websites was still minute compared to present standards, quite a number of notable websites were already active, many of which are the precursors or inspiration for today's most popular services.
Connected by the existing Internet, other websites were created around the world, adding international standards for domain name
Domain name
A domain name is an identification string that defines a realm of administrative autonomy, authority, or control in the Internet. Domain names are formed by the rules and procedures of the Domain Name System ....
s and HTML
HTML
HyperText Markup Language is the predominant markup language for web pages. HTML elements are the basic building-blocks of webpages....
. Since then, Berners-Lee has played an active role in guiding the development of web standards (such as the markup language
Markup language
A markup language is a modern system for annotating a text in a way that is syntactically distinguishable from that text. The idea and terminology evolved from the "marking up" of manuscripts, i.e. the revision instructions by editors, traditionally written with a blue pencil on authors' manuscripts...
s in which web pages are composed), and in recent years has advocated his vision of a Semantic Web
Semantic Web
The Semantic Web is a collaborative movement led by the World Wide Web Consortium that promotes common formats for data on the World Wide Web. By encouraging the inclusion of semantic content in web pages, the Semantic Web aims at converting the current web of unstructured documents into a "web of...
. The World Wide Web enabled the spread of information over the Internet through an easy-to-use and flexible format. It thus played an important role in popularizing use of the Internet. Although the two terms are sometimes conflated
Conflation
Conflation occurs when the identities of two or more individuals, concepts, or places, sharing some characteristics of one another, become confused until there seems to be only a single identity — the differences appear to become lost...
in popular use, World Wide Web is not synonym
Synonym
Synonyms are different words with almost identical or similar meanings. Words that are synonyms are said to be synonymous, and the state of being a synonym is called synonymy. The word comes from Ancient Greek syn and onoma . The words car and automobile are synonyms...
ous with Internet. The Web is a collection of documents and both client and server software using Internet protocols such as TCP/IP and HTTP.
Function
The terms Internet and World Wide Web are often used in every-day speech without much distinction. However, the Internet and the World Wide Web are not one and the same. The Internet is a global system of interconnected computer networks. In contrast, the Web is one of the services that runs on the Internet. It is a collection of textual documents and other resources, linked by hyperlinks and URLs, transmitted by web browsers and web servers. In short, the Web can be thought of as an applicationApplication software
Application software, also known as an application or an "app", is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with...
"running" on the Internet.
Viewing a web page
Web page
A web page or webpage is a document or information resource that is suitable for the World Wide Web and can be accessed through a web browser and displayed on a monitor or mobile device. This information is usually in HTML or XHTML format, and may provide navigation to other web pages via hypertext...
on the World Wide Web normally begins either by typing the URL
Uniform Resource Locator
In computing, a uniform resource locator or universal resource locator is a specific character string that constitutes a reference to an Internet resource....
of the page into a web browser
Web browser
A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...
or by following a hyperlink
Hyperlink
In computing, a hyperlink is a reference to data that the reader can directly follow, or that is followed automatically. A hyperlink points to a whole document or to a specific element within a document. Hypertext is text with hyperlinks...
to that page or resource. The web browser then initiates a series of communication messages, behind the scenes, in order to fetch and display it. As an example, consider the Wikipedia page for this article with the URL
First, the browser resolves the server-name portion of the URL (en.wikipedia.org) into an Internet Protocol address
IP address
An Internet Protocol address is a numerical label assigned to each device participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host or network interface identification and location addressing...
using the globally distributed database known as the Domain Name System
Domain name system
The Domain Name System is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities...
(DNS); this lookup returns an IP address such as 208.80.152.2. The browser then requests the resource by sending an HTTP
Hypertext Transfer Protocol
The Hypertext Transfer Protocol is a networking protocol for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web....
request across the Internet to the computer at that particular address. It makes the request to a particular application port in the underlying Internet Protocol Suite
Internet protocol suite
The Internet protocol suite is the set of communications protocols used for the Internet and other similar networks. It is commonly known as TCP/IP from its most important protocols: Transmission Control Protocol and Internet Protocol , which were the first networking protocols defined in this...
so that the computer receiving the request can distinguish an HTTP request from other network protocols it may be servicing such as e-mail delivery; the HTTP protocol normally uses port 80. The content of the HTTP request can be as simple as the two lines of text
GET /wiki/World_Wide_Web HTTP/1.1
Host: en.wikipedia.org
The computer receiving the HTTP request delivers it to Web server
Web server
Web server can refer to either the hardware or the software that helps to deliver content that can be accessed through the Internet....
software listening for requests on port 80. If the web server can fulfill the request it sends an HTTP response back to the browser indicating success, which can be as simple as
HTTP/1.0 200 OK
Content-Type: text/html; charset=UTF-8
followed by the content of the requested page. The Hypertext Markup Language for a basic web page looks like
The World Wide Web, abbreviated as WWW and commonly known ...
The web browser parses
Parsing
In computer science and linguistics, parsing, or, more formally, syntactic analysis, is the process of analyzing a text, made of a sequence of tokens , to determine its grammatical structure with respect to a given formal grammar...
the HTML, interpreting the markup (
Many web pages consist of more elaborate HTML which references the URLs of other resources such as images, other embedded media, scripts
JavaScript
JavaScript is a prototype-based scripting language that is dynamic, weakly typed and has first-class functions. It is a multi-paradigm language, supporting object-oriented, imperative, and functional programming styles....
that affect page behavior, and Cascading Style Sheets
Cascading Style Sheets
Cascading Style Sheets is a style sheet language used to describe the presentation semantics of a document written in a markup language...
that affect page layout. A browser that handles complex HTML will make additional HTTP requests to the web server for these other Internet media type
Internet media type
An Internet media type, originally called a MIME type after MIME and sometimes a Content-type after the name of a header in several protocols whose value is such a type, is a two-part identifier for file formats on the Internet.The identifiers were originally defined in RFC 2046 for use in email...
s. As it receives their content from the web server, the browser progressively renders
Layout engine
A web browser engine, , is a software component that takes marked up content and formatting information and displays the formatted content on the screen. It "paints" on the content area of a window, which is displayed on a monitor or a printer...
the page onto the screen as specified by its HTML and these additional resources.
Linking
Most web pages contain hyperlinks to other related pages and perhaps to downloadable files, source documents, definitions and other web resources (this Wikipedia article is full of hyperlinks). In the underlying HTML, a hyperlink looks likeof the first Web site
Such a collection of useful, related resources, interconnected via hypertext links is dubbed a web of information. Publication on the Internet created what Tim Berners-Lee
Tim Berners-Lee
Sir Timothy John "Tim" Berners-Lee, , also known as "TimBL", is a British computer scientist, MIT professor and the inventor of the World Wide Web...
first called the WorldWideWeb (in its original CamelCase
CamelCase
CamelCase , also known as medial capitals, is the practice of writing compound words or phrases in which the elements are joined without spaces, with each element's initial letter capitalized within the compound and the first letter either upper or lower case—as in "LaBelle", "BackColor",...
, which was subsequently discarded) in November 1990.
The hyperlink structure of the WWW is described by the webgraph
Webgraph
The webgraph describes the directed links between pages of the World Wide Web. A graph, in general, consists of several vertices, some pairs connected by edges. In a directed graph, edges are directed lines or arcs...
: the nodes of the webgraph
Webgraph
The webgraph describes the directed links between pages of the World Wide Web. A graph, in general, consists of several vertices, some pairs connected by edges. In a directed graph, edges are directed lines or arcs...
correspond to the web pages (or URLs) the directed edges between them to the hyperlink
Hyperlink
In computing, a hyperlink is a reference to data that the reader can directly follow, or that is followed automatically. A hyperlink points to a whole document or to a specific element within a document. Hypertext is text with hyperlinks...
s.
Over time, many web resources pointed to by hyperlinks disappear, relocate, or are replaced with different content. This makes hyperlinks obsolete, a phenomenon referred to in some circles as link rot
Link rot
Link rot , also known as link death or link breaking is an informal term for the process by which, either on individual websites or the Internet in general, increasing numbers of links point to web pages, servers or other resources that have become permanently unavailable...
and the hyperlinks affected by it are often called dead links. The ephemeral nature of the Web has prompted many efforts to archive web sites. The Internet Archive
Internet Archive
The Internet Archive is a non-profit digital library with the stated mission of "universal access to all knowledge". It offers permanent storage and access to collections of digitized materials, including websites, music, moving images, and nearly 3 million public domain books. The Internet Archive...
, active since 1996, is one of the best-known efforts.
Dynamic updates of web pages
JavaScriptJavaScript
JavaScript is a prototype-based scripting language that is dynamic, weakly typed and has first-class functions. It is a multi-paradigm language, supporting object-oriented, imperative, and functional programming styles....
is a scripting language that was initially developed in 1995 by Brendan Eich
Brendan Eich
Brendan Eich is a computer programmer and creator of the JavaScript scripting language. He is the chief technology officer at the Mozilla Corporation.-Education:...
, then of Netscape
Netscape
Netscape Communications is a US computer services company, best known for Netscape Navigator, its web browser. When it was an independent company, its headquarters were in Mountain View, California...
, for use within web pages. The standardized version is ECMAScript
ECMAScript
ECMAScript is the scripting language standardized by Ecma International in the ECMA-262 specification and ISO/IEC 16262. The language is widely used for client-side scripting on the web, in the form of several well-known dialects such as JavaScript, JScript, and ActionScript.- History :JavaScript...
. To overcome some of the limitations of the page-by-page model described above, some web applications also use Ajax
Ajax (programming)
Ajax is a group of interrelated web development methods used on the client-side to create asynchronous web applications...
(asynchronous
Asynchronous I/O
Asynchronous I/O, or non-blocking I/O, is a form of input/output processing that permits other processing to continue before the transmission has finished....
JavaScript and XML
XML
Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....
). JavaScript is delivered with the page that can make additional HTTP requests to the server, either in response to user actions such as mouse-clicks or based on lapsed time. The server's responses are used to modify the current page rather than creating a new page with each response. Thus, the server must provide only limited, incremental information. Since multiple Ajax requests can be handled at the same time, users can interact with a page even while data is being retrieved. Some web applications regularly poll
Polling (computer science)
Polling, or polled operation, in computer science, refers to actively sampling the status of an external device by a client program as a synchronous activity. Polling is most often used in terms of input/output , and is also referred to as polled or software driven .Polling is sometimes used...
the server to ask whether new information is available.
WWW prefix
Many domain names used for the World Wide Web begin with www because of the long-standing practice of naming Internet hosts (servers) according to the services they provide. The hostnameHostname
A hostname is a label that is assigned to a device connected to a computer network and that is used to identify the device in various forms of electronic communication such as the World Wide Web, e-mail or Usenet...
for a web server
Web server
Web server can refer to either the hardware or the software that helps to deliver content that can be accessed through the Internet....
is often www, in the same way that it may be ftp for an FTP server, and news or nntp for a USENET
Usenet
Usenet is a worldwide distributed Internet discussion system. It developed from the general purpose UUCP architecture of the same name.Duke University graduate students Tom Truscott and Jim Ellis conceived the idea in 1979 and it was established in 1980...
news server
News server
A news server is a set of computer software used to handle Usenet articles. It may also refer to a computer itself which is primarily or solely used for handling Usenet. A reader server provides an interface to read and post articles, generally with the assistance of a news client. A transit...
. These host names appear as Domain Name System
Domain name system
The Domain Name System is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities...
(DNS) subdomain
Subdomain
In the Domain Name System hierarchy, a subdomain is a domain that is part of a larger domain.- Overview :The Domain Name System has a tree structure or hierarchy, with each node on the tree being a domain name. A subdomain is a domain that is part of a larger domain, the only domain that is not...
names, as in www.example.com. The use of 'www' as a subdomain name is not required by any technical or policy standard; indeed, the first ever web server was called nxoc01.cern.ch, and many web sites exist without it. Many established websites still use 'www', or they invent other subdomain names such as 'www2', 'secure', etc. Many such web servers are set up such that both the domain root (e.g., example.com) and the www subdomain (e.g., www.example.com) refer to the same site; others require one form or the other, or they may map to different web sites.
The use of a subdomain name is useful for load balancing
Load balancing (computing)
Load balancing is a computer networking methodology to distribute workload across multiple computers or a computer cluster, network links, central processing units, disk drives, or other resources, to achieve optimal resource utilization, maximize throughput, minimize response time, and avoid...
incoming web traffic by creating a CNAME record
CNAME record
A CNAME record or Canonical Name record is a type of resource record in the Domain Name System that specifies that the domain name is an alias of another, canonical domain name. This helps when running multiple services from a single IP address...
that points to a cluster of web servers. Since, currently, only a subdomain can be cname'ed, the same result cannot be achieved by using the bare domain root.
When a user submits an incomplete domain name to a web browser in its address bar input field, some web browsers automatically try adding the prefix "www" to the beginning of it and possibly ".com", ".org" and ".net" at the end, depending on what might be missing. For example, entering '' may be transformed to
Lynx (web browser)
Lynx is a text-based web browser for use on cursor-addressable character cell terminals and is very configurable.-Usage:Browsing in Lynx consists of highlighting the chosen link using cursor keys, or having all links on a page numbered and entering the chosen link's number. Current versions support...
. It is reported that Microsoft was granted a US patent for the same idea in 2008, but only for mobile devices.
In English, www is pronounced by individually pronouncing the name of characters (double-u double-u double-u) or by saying the phrase "triple double-u". Although some technical users pronounce it dub-dub-dub, this is not widespread. The English writer Douglas Adams
Douglas Adams
Douglas Noel Adams was an English writer and dramatist. He is best known as the author of The Hitchhiker's Guide to the Galaxy, which started life in 1978 as a BBC radio comedy before developing into a "trilogy" of five books that sold over 15 million copies in his lifetime, a television...
once quipped in The Independent on Sunday
The Independent
The Independent is a British national morning newspaper published in London by Independent Print Limited, owned by Alexander Lebedev since 2010. It is nicknamed the Indy, while the Sunday edition, The Independent on Sunday, is the Sindy. Launched in 1986, it is one of the youngest UK national daily...
(1999): "The World Wide Web is the only thing I know of whose shortened form takes three times longer to say than what it's short for," with Stephen Fry later pronouncing it in his "Podgrammes" series of podcasts as "wuh wuh wuh." In Mandarin Chinese, World Wide Web is commonly translated via a phono-semantic matching
Phono-semantic matching
Phono-semantic matching is a linguistic term referring to camouflaged borrowing in which a foreign word is matched with a phonetically and semantically similar pre-existent native word/root....
to wàn wéi wǎng , which satisfies www and literally means "myriad dimensional net", a translation that very appropriately reflects the design concept and proliferation of the World Wide Web. Tim Berners-Lee's web-space states that World Wide Web is officially spelled as three separate words, each capitalized, with no intervening hyphens.
Use of the www prefix is declining as Web 2.0
Web 2.0
The term Web 2.0 is associated with web applications that facilitate participatory information sharing, interoperability, user-centered design, and collaboration on the World Wide Web...
web application
Web application
A web application is an application that is accessed over a network such as the Internet or an intranet. The term may also mean a computer software application that is coded in a browser-supported language and reliant on a common web browser to render the application executable.Web applications are...
s seek to brand
Brand
The American Marketing Association defines a brand as a "Name, term, design, symbol, or any other feature that identifies one seller's good or service as distinct from those of other sellers."...
their domain names and make them easily pronounceable. As the mobile web
Mobile Web
The Mobile Web refers to the use of Internet-connected applications, or browser-based access to the Internet from a mobile device, such as a smartphone or tablet computer, connected to a wireless network....
grows in popularity, services like Gmail.com, MySpace
MySpace
Myspace is a social networking service owned by Specific Media LLC and pop star Justin Timberlake. Myspace launched in August 2003 and is headquartered in Beverly Hills, California. In August 2011, Myspace had 33.1 million unique U.S. visitors....
.com, Facebook
Facebook
Facebook is a social networking service and website launched in February 2004, operated and privately owned by Facebook, Inc. , Facebook has more than 800 million active users. Users must register before using the site, after which they may create a personal profile, add other users as...
.com and Twitter
Twitter
Twitter is an online social networking and microblogging service that enables its users to send and read text-based posts of up to 140 characters, informally known as "tweets".Twitter was created in March 2006 by Jack Dorsey and launched that July...
.com are most often discussed without adding the www to the domain (or the .com)
http and https specifiers
The scheme specifiers (Uniform Resource Identifier
In computing, a uniform resource identifier is a string of characters used to identify a name or a resource on the Internet. Such identification enables interaction with representations of the resource over a network using specific protocols...
refer to the Hypertext Transfer Protocol
Hypertext Transfer Protocol
The Hypertext Transfer Protocol is a networking protocol for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web....
and to HTTP Secure, respectively, and so define the communication protocol to be used for the request and response. The HTTP protocol is fundamental to the operation of the World Wide Web; the added encryption layer in HTTPS is essential when confidential information such as passwords or banking information are to be exchanged over the public Internet. Web browsers usually prepend the scheme to URLs too, if omitted.
Privacy
It is possible that, average computer users who use the World Wide Web mainly for things like entertainment, may have surrendered the right to privacy in exchange for using a number of services available on the World Wide Web. For example: more than half a billion people worldwide have used a social network serviceSocial network service
A social networking service is an online service, platform, or site that focuses on building and reflecting of social networks or social relations among people, who, for example, share interests and/or activities. A social network service consists of a representation of each user , his/her social...
, and of the generations of people within the United States who have had access to the internet from a young age, half have some form of Social Networking presence. and are part of a generational shift that could be changing norms. The social network Facebook progressed from U.S. college students to a 70% non-U.S. audience, but in 2009 estimated that only 20% of its members use privacy settings. In 2010 (six years after co-founding the company), Mark Zuckerberg
Mark Zuckerberg
Mark Elliot Zuckerberg is an American computer programmer and Internet entrepreneur. He is best known for co-creating the social networking site Facebook, of which he is chief executive and president...
wrote, "we will add privacy controls that are much simpler to use".
Privacy representatives from 60 countries have resolved to ask for laws to complement industry self-regulation, for education for children and other minors who use the Web, and for default protections for users of social networks. They also believe data protection for personally identifiable information
Personally identifiable information
Personally Identifiable Information , as used in information security, is information that can be used to uniquely identify, contact, or locate a single person or can be used with other sources to uniquely identify a single individual...
benefits business more than the sale of that information. Users can opt-in to features in browsers to clear their personal histories locally and block some cookies
HTTP cookie
A cookie, also known as an HTTP cookie, web cookie, or browser cookie, is used for an origin website to send state information to a user's browser and for the browser to return the state information to the origin site...
and advertising network
Advertising network
An online advertising network or ad network is a company that connects advertisers to web sites that want to host advertisements. The key function of an ad network is aggregation of ad space supply from publishers and matching it with advertiser demand...
s but they are still tracked in websites' server log
Server log
A server log is a log file automatically created and maintained by a server of activity performed by it.A typical example is a web server log which maintains a history of page requests. The W3C maintains a standard format for web server log files, but other proprietary formats exist...
s, and in particular web beacons. Berners-Lee and colleagues see hope in accountability and appropriate use achieved by extending the Web's architecture to policy awareness, perhaps with audit logging, reasoners and appliances.
In exchange for providing free content, vendors hire advertisers who spy on Web users and base their business model on tracking them. Since 2009, they buy and sell consumer data on exchanges (lacking a few details that could make it possible to de-anonymize, or identify an individual). Hundreds of millions of times per day, Lotame Solutions captures what users are typing in real time, and sends that text to OpenAmplify who then tries to determine, to quote a writer at The Wall Street Journal
The Wall Street Journal
The Wall Street Journal is an American English-language international daily newspaper. It is published in New York City by Dow Jones & Company, a division of News Corporation, along with the Asian and European editions of the Journal....
, "what topics are being discussed, how the author feels about those topics, and what the person is going to do about them".
Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
backed away in 2008 from its plans for strong privacy features in Internet Explorer, leaving its users (50% of the world's Web users) open to advertisers who may make assumptions about them based on only one click when they visit a website. Among services paid for by advertising, Yahoo!
Yahoo!
Yahoo! Inc. is an American multinational internet corporation headquartered in Sunnyvale, California, United States. The company is perhaps best known for its web portal, search engine , Yahoo! Directory, Yahoo! Mail, Yahoo! News, Yahoo! Groups, Yahoo! Answers, advertising, online mapping ,...
could collect the most data about users of commercial websites, about 2,500 bits of information per month about each typical user of its site and its affiliated advertising network sites. Yahoo! was followed by MySpace with about half that potential and then by AOL
AOL
AOL Inc. is an American global Internet services and media company. AOL is headquartered at 770 Broadway in New York. Founded in 1983 as Control Video Corporation, it has franchised its services to companies in several nations around the world or set up international versions of its services...
–TimeWarner, Google
Google
Google Inc. is an American multinational public corporation invested in Internet search, cloud computing, and advertising technologies. Google hosts and develops a number of Internet-based services and products, and generates profit primarily from advertising through its AdWords program...
, Facebook, Microsoft, and eBay
EBay
eBay Inc. is an American internet consumer-to-consumer corporation that manages eBay.com, an online auction and shopping website in which people and businesses buy and sell a broad variety of goods and services worldwide...
.
Security
The Web has become criminals' preferred pathway for spreading malwareMalware
Malware, short for malicious software, consists of programming that is designed to disrupt or deny operation, gather information that leads to loss of privacy or exploitation, or gain unauthorized access to system resources, or that otherwise exhibits abusive behavior...
. Cybercrime carried out on the Web can include identity theft
Identity theft
Identity theft is a form of stealing another person's identity in which someone pretends to be someone else by assuming that person's identity, typically in order to access resources or obtain credit and other benefits in that person's name...
, fraud
Fraud
In criminal law, a fraud is an intentional deception made for personal gain or to damage another individual; the related adjective is fraudulent. The specific legal definition varies by legal jurisdiction. Fraud is a crime, and also a civil law violation...
, espionage and intelligence gathering. Web-based vulnerabilities
Vulnerability (computing)
In computer security, a vulnerability is a weakness which allows an attacker to reduce a system's information assurance.Vulnerability is the intersection of three elements: a system susceptibility or flaw, attacker access to the flaw, and attacker capability to exploit the flaw...
now outnumber traditional computer security concerns, and as measured by Google
Google
Google Inc. is an American multinational public corporation invested in Internet search, cloud computing, and advertising technologies. Google hosts and develops a number of Internet-based services and products, and generates profit primarily from advertising through its AdWords program...
, about one in ten web pages may contain malicious code. Most Web-based attacks
Attack (computer)
In computer and computer networks an attack is any attempt to destroy, expose, alter, disable, steal or gain unauthorized access to or make unauthorized use of an asset.- IETF :Internet Engineering Task Force defines attack in RFC 2828 as:...
take place on legitimate websites, and most, as measured by Sophos
Sophos
Sophos is a developer and vendor of security software and hardware, including anti-virus, anti-spyware, anti-spam, network access control, encryption software and data loss prevention for desktops, servers, email systems and other network gateways....
, are hosted in the United States, China and Russia. The most common of all malware threats
Threat (computer)
In Computer security a threat is a possible danger that might exploit a vulnerability to breach security and thus cause possible harm.A threat can be either "intentional" or "accidental" In Computer security a threat is a possible danger that might exploit a vulnerability to breach security and...
is SQL injection
SQL injection
A SQL injection is often used to attack the security of a website by inputting SQL statements in a web form to get a badly designed website in order to dump the database content to the attacker. SQL injection is a code injection technique that exploits a security vulnerability in a website's software...
attacks against websites. Through HTML and URIs the Web was vulnerable to attacks like cross-site scripting
Cross-site scripting
Cross-site scripting is a type of computer security vulnerability typically found in Web applications that enables attackers to inject client-side script into Web pages viewed by other users. A cross-site scripting vulnerability may be used by attackers to bypass access controls such as the same...
(XSS) that came with the introduction of JavaScript and were exacerbated to some degree by Web 2.0 and Ajax web design
Web design
Web design is the process of planning and creating a website. Text, images, digital media and interactive elements are used by web designers to produce the page seen on the web browser...
that favors the use of scripts. Today by one estimate, 70% of all websites are open to XSS attacks on their users.
Proposed solutions vary to extremes. Large security vendors like McAfee
McAfee
McAfee, Inc. is a computer security company headquartered in Santa Clara, California, USA. It markets software and services to home users, businesses and the public sector. On August 19, 2010, electronics company Intel agreed to purchase McAfee for $7.68 billion...
already design governance and compliance suites to meet post-9/11 regulations, and some, like Finjan
Finjan
Update: Finjan is now part of .Founded in 1996, Finjan was headquartered in San Jose, California before being acquired by M86 Security in 2009...
have recommended active real-time inspection of code and all content regardless of its source. Some have argued that for enterprise to see security as a business opportunity rather than a cost center, "ubiquitous, always-on digital rights management" enforced in the infrastructure by a handful of organizations must replace the hundreds of companies that today secure data and networks. Jonathan Zittrain
Jonathan Zittrain
Jonathan L. Zittrain is a US professor of Internet law at Harvard Law School and the Harvard Kennedy School, a professor of computer science at the Harvard School of Engineering and Applied Sciences, and a faculty co-director of Harvard's Berkman Center for Internet & Society...
has said users sharing responsibility for computing safety is far preferable to locking down the Internet.
Standards
Many formal standards and other technical specifications and software define the operation of different aspects of the World Wide Web, the Internet, and computer information exchange. Many of the documents are the work of the World Wide Web Consortium (W3C), headed by Berners-Lee, but some are produced by the Internet Engineering Task ForceInternet Engineering Task Force
The Internet Engineering Task Force develops and promotes Internet standards, cooperating closely with the W3C and ISO/IEC standards bodies and dealing in particular with standards of the TCP/IP and Internet protocol suite...
(IETF) and other organizations.
Usually, when web standards are discussed, the following publications are seen as foundational:
- Recommendations for markup languages, especially HTMLHTMLHyperText Markup Language is the predominant markup language for web pages. HTML elements are the basic building-blocks of webpages....
and XHTMLXHTMLXHTML is a family of XML markup languages that mirror or extend versions of the widely-used Hypertext Markup Language , the language in which web pages are written....
, from the W3C. These define the structure and interpretation of hypertextHypertextHypertext is text displayed on a computer or other electronic device with references to other text that the reader can immediately access, usually by a mouse click or keypress sequence. Apart from running text, hypertext may contain tables, images and other presentational devices. Hypertext is the...
documents. - Recommendations for stylesheets, especially CSSCascading Style SheetsCascading Style Sheets is a style sheet language used to describe the presentation semantics of a document written in a markup language...
, from the W3C. - Standards for ECMAScriptECMAScriptECMAScript is the scripting language standardized by Ecma International in the ECMA-262 specification and ISO/IEC 16262. The language is widely used for client-side scripting on the web, in the form of several well-known dialects such as JavaScript, JScript, and ActionScript.- History :JavaScript...
(usually in the form of JavaScriptJavaScriptJavaScript is a prototype-based scripting language that is dynamic, weakly typed and has first-class functions. It is a multi-paradigm language, supporting object-oriented, imperative, and functional programming styles....
), from Ecma InternationalEcma InternationalEcma International is an international, private non-profit standards organization for information and communication systems. It acquired its name in 1994, when the European Computer Manufacturers Association changed its name to reflect the organization's global reach and activities...
. - Recommendations for the Document Object ModelDocument Object ModelThe Document Object Model is a cross-platform and language-independent convention for representing and interacting with objects in HTML, XHTML and XML documents. Aspects of the DOM may be addressed and manipulated within the syntax of the programming language in use...
, from W3C.
Additional publications provide definitions of other essential technologies for the World Wide Web, including, but not limited to, the following:
- Uniform Resource Identifier (URIUniform Resource IdentifierIn computing, a uniform resource identifier is a string of characters used to identify a name or a resource on the Internet. Such identification enables interaction with representations of the resource over a network using specific protocols...
), which is a universal system for referencing resources on the Internet, such as hypertext documents and images. URIs, often called URLs, are defined by the IETF's RFC 3986 / STD 66: Uniform Resource Identifier (URI): Generic Syntax, as well as its predecessors and numerous URI schemeURI schemeIn the field of computer networking, a URI scheme is the top level of the Uniform Resource Identifier naming structure. All URIs and absolute URI references are formed with a scheme name, followed by a colon character , and the remainder of the URI called the scheme-specific part...
-defining RFCsRequest for CommentsIn computer network engineering, a Request for Comments is a memorandum published by the Internet Engineering Task Force describing methods, behaviors, research, or innovations applicable to the working of the Internet and Internet-connected systems.Through the Internet Society, engineers and...
; - HyperText Transfer Protocol (HTTP), especially as defined by RFC 2616: HTTP/1.1 and RFC 2617: HTTP Authentication, which specify how the browser and server authenticate each other.
Accessibility
Access to the Web is for everyone regardless of disability—including visual, auditory, physical, speech, cognitive, and neurological. Accessibility features also help others with temporary disabilities like a broken arm or the aging population as their abilities change. The Web is used for receiving information as well as providing information and interacting with society, making it essential that the Web be accessible in order to provide equal access and equal opportunityEqual opportunity
Equal opportunity, or equality of opportunity, is a controversial political concept; and an important informal decision-making standard without a precise definition involving fair choices within the public sphere...
to people with disabilities. Tim Berners-Lee once noted, "The power of the Web is in its universality. Access by everyone regardless of disability is an essential aspect." Many countries regulate web accessibility
Web accessibility
Web accessibility refers to the inclusive practice of making websites usable by people of all abilities and disabilities. When sites are correctly designed, developed and edited, all users can have equal access to information and functionality...
as a requirement for websites. International cooperation in the W3C Web Accessibility Initiative
Web Accessibility Initiative
The World Wide Web Consortium 's Web Accessibility Initiative is an effort to improve the accessibility of the World Wide Web for people with disabilities...
led to simple guidelines that web content authors as well as software developers can use to make the Web accessible to persons who may or may not be using assistive technology
Assistive technology
Assistive technology or adaptive technology is an umbrella term that includes assistive, adaptive, and rehabilitative devices for people with disabilities and also includes the process used in selecting, locating, and using them...
.
Internationalization
The W3C InternationalizationInternationalization and localization
In computing, internationalization and localization are means of adapting computer software to different languages, regional differences and technical requirements of a target market...
Activity assures that web technology will work in all languages, scripts, and cultures. Beginning in 2004 or 2005, Unicode
Unicode
Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...
gained ground and eventually in December 2007 surpassed both ASCII
ASCII
The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
and Western European as the Web's most frequently used character encoding
Character encoding
A character encoding system consists of a code that pairs each character from a given repertoire with something else, such as a sequence of natural numbers, octets or electrical pulses, in order to facilitate the transmission of data through telecommunication networks or storage of text in...
. Originally RFC 3986 allowed resources to be identified by URI
Úri
Úriis a village and commune in the comitatus of Pest in Hungary....
in a subset of US-ASCII. RFC 3987 allows more characters—any character in the Universal Character Set
Universal Character Set
The Universal Character Set , defined by the International Standard ISO/IEC 10646, Information technology — Universal multiple-octet coded character set , is a standard set of characters upon which many character encodings are based...
—and now a resource can be identified by IRI
Internationalized Resource Identifier
On the Internet, the Internationalized Resource Identifier is a generalization of the Uniform Resource Identifier . While URIs are limited to a subset of the ASCII character set, IRIs may contain characters from the Universal Character Set , including Chinese or Japanese kanji, Korean, Cyrillic...
in any language.
Statistics
Between 2005 and 2010, the number of Web users doubled, and was expected to surpass two billion in 2010. According to a 2001 study, there were a massive number, over 550 billion, of documents on the Web, mostly in the invisible Web, or Deep WebDeep web
The Deep Web refers to World Wide Web content that is not part of the Surface Web, which is indexed by standard search engines....
. A 2002 survey of 2,024 million Web pages determined that by far the most Web content was in English: 56.4%; next were pages in German (7.7%), French (5.6%), and Japanese (4.9%). A more recent study, which used Web searches in 75 different languages to sample the Web, determined that there were over 11.5 billion Web pages in the publicly indexable Web
Surface web
The surface Web is that portion of the World Wide Web that is indexed by conventional search engines. The part of the Web that is not reachable this way is called the Deep Web. Search engines construct a database of the Web by using programs called spiders or Web crawlers that begin with a list of...
as of the end of January 2005. , the indexable web contains at least 25.21 billion pages. On July 25, 2008, Google software engineers Jesse Alpert and Nissan Hajaj announced that Google Search
Google search
Google or Google Web Search is a web search engine owned by Google Inc. Google Search is the most-used search engine on the World Wide Web, receiving several hundred million queries each day through its various services....
had discovered one trillion unique URLs. , over 109.5 million domains operated. Of these 74% were commercial or other sites operating in the
.com
generic top-level domainGeneric top-level domain
A generic top-level domain is one of the categories of top-level domains maintained by the Internet Assigned Numbers Authority for use in the Domain Name System of the Internet....
.
Statistics measuring a website's popularity are usually based either on the number of page view
Page view
A page view or page impression is a request to load a single HTML file of an Internet site. On the World Wide Web a 'page' request would result from a web surfer clicking on a link on another 'page' pointing to the 'page' in question. This should be contrasted with a hit, which refers to a...
s or on associated server 'hits
Hit (internet)
A hit is a request to a web server for a file . When a web page is uploaded from a server the number of "hits" or "page hits" is equal to the number of files requested. Therefore, one page load does not always equal one hit because often pages are made up of other images and other files which stack...
' (file requests) that it receives.
Speed issues
Frustration over congestionNetwork congestion
In data networking and queueing theory, network congestion occurs when a link or node is carrying so much data that its quality of service deteriorates. Typical effects include queueing delay, packet loss or the blocking of new connections...
issues in the Internet infrastructure and the high latency
Latency (engineering)
Latency is a measure of time delay experienced in a system, the precise definition of which depends on the system and the time being measured. Latencies may have different meaning in different contexts.-Packet-switched networks:...
that results in slow browsing has led to a pejorative name for the World Wide Web: the World Wide Wait. Speeding up the Internet is an ongoing discussion over the use of peering
Peering
In computer networking, peering is a voluntary interconnection of administratively separate Internet networks for the purpose of exchanging traffic between the customers of each network. The pure definition of peering is settlement-free or "sender keeps all," meaning that neither party pays the...
and QoS
Quality of service
The quality of service refers to several related aspects of telephony and computer networks that allow the transport of traffic with special requirements...
technologies. Other solutions to reduce the congestion can be found at W3C. Guideline
Guideline
A guideline is a statement by which to determine a course of action. A guideline aims to streamline particular processes according to a set routine or sound practice. By definition, following a guideline is never mandatory. Guidelines are not binding and are not enforced. A guideline is a statement...
s for Web response times are:
- 0.1 second (one tenth of a second). Ideal response time. The user does not sense any interruption.
- 1 second. Highest acceptable response time. Download times above 1 second interrupt the user experience.
- 10 seconds. Unacceptable response time. The user experience is interrupted and the user is likely to leave the site or system.
Caching
If a user revisits a Web page after only a short interval, the page data may not need to be re-obtained from the source Web server. Almost all web browsers cacheCache
In computer engineering, a cache is a component that transparently stores data so that future requests for that data can be served faster. The data that is stored within a cache might be values that have been computed earlier or duplicates of original values that are stored elsewhere...
recently obtained data, usually on the local hard drive. HTTP requests sent by a browser will usually ask only for data that has changed since the last download. If the locally cached data are still current, it will be reused. Caching helps reduce the amount of Web traffic on the Internet. The decision about expiration is made independently for each downloaded file, whether image, stylesheet
Cascading Style Sheets
Cascading Style Sheets is a style sheet language used to describe the presentation semantics of a document written in a markup language...
, JavaScript
JavaScript
JavaScript is a prototype-based scripting language that is dynamic, weakly typed and has first-class functions. It is a multi-paradigm language, supporting object-oriented, imperative, and functional programming styles....
, HTML, or whatever other content the site may provide. Thus even on sites with highly dynamic content, many of the basic resources need to be refreshed only occasionally. Web site designers find it worthwhile to collate resources such as CSS data and JavaScript into a few site-wide files so that they can be cached efficiently. This helps reduce page download times and lowers demands on the Web server.
There are other components of the Internet that can cache Web content. Corporate and academic firewalls often cache Web resources requested by one user for the benefit of all. (See also Caching proxy server.) Some search engines also store cached content from websites. Apart from the facilities built into Web servers that can determine when files have been updated and so need to be re-sent, designers of dynamically generated Web pages can control the HTTP headers sent back to requesting users, so that transient or sensitive pages are not cached. Internet banking
Online banking
Online banking allows customers to conduct financial transactions on a secure website operated by their retail or virtual bank, credit union or building society.-Features:...
and news sites frequently use this facility. Data requested with an HTTP
Hypertext Transfer Protocol
The Hypertext Transfer Protocol is a networking protocol for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web....
'GET' is likely to be cached if other conditions are met; data obtained in response to a 'POST' is assumed to depend on the data that was POSTed and so is not cached.
See also
- Electronic publishingElectronic publishingElectronic publishing or ePublishing includes the digital publication of e-books and electronic articles, and the development of digital libraries and catalogues. Electronic publishing has become common in scientific publishing where it has been argued that peer-reviewed scientific journals are in...
- Lists of websites
- PrestelPrestelPrestel , the brand name for the UK Post Office's Viewdata technology, was an interactive videotex system developed during the late 1970s and commercially launched in 1979...
- Streaming mediaStreaming mediaStreaming media is multimedia that is constantly received by and presented to an end-user while being delivered by a streaming provider.The term "presented" is used in this article in a general sense that includes audio or video playback. The name refers to the delivery method of the medium rather...
- Web 1.0Web 1.0Web 1.0, or web, refers to the first stage of the World Wide Web linking webpages with hyperlinks.- History :Hyperlinks between webpages began with the release of the WWW to the public in 1993, and describe the Web before the "bursting of the Dot-com bubble" in 2001.Since 2004, Web 2.0 has been the...
- WebgraphWebgraphThe webgraph describes the directed links between pages of the World Wide Web. A graph, in general, consists of several vertices, some pairs connected by edges. In a directed graph, edges are directed lines or arcs...
Further reading
- Niels Brügger, ed. Web History (2010) 362 pages; Historical perspective on the World Wide Web, including issues of culture, content, and preservation.
External links
- Early archive of the first Web site
- Internet Statistics: Growth and Usage of the Web and the Internet
- Living Internet A comprehensive history of the Internet, including the World Wide Web.
- World Wide Web Consortium
- World Wide Web Size Daily estimated size of the World Wide Web.
- Antonio A. Casilli, Some Elements for a Sociology of Online Interactions
- The Erdős Webgraph Server offers weekly updated graph representation of a constantly increasing fraction of the WWW.