Web feed - AbsoluteAstronomy.com

A web feed is a data format used for providing users with frequently updated content. Content distributors syndicate
Web syndication
Web syndication is a form of syndication in which website material is made available to multiple other sites. Most commonly, web syndication refers to making web feeds available from a site in order to provide other people with a summary or update of the website's recently added content...

a web feed, thereby allowing users to subscribe to it. Making a collection of web feeds accessible in one spot is known as aggregation, which is performed by an aggregator. A web feed is also sometimes referred to as a syndicated feed.

A typical scenario of web feed use is: a content provider publishes a feed link on their site which end users can register with an aggregator program (also called a feed reader or a news reader) running on their own machines; doing this is usually as simple as dragging the link from the 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...

to the aggregator. When instructed, the aggregator asks all the servers in its feed list if they have new content; if so, the aggregator either makes a note of the new content or downloads it. Aggregators can be scheduled to check for new content periodically. Web feeds are an example of pull technology

Pull technology

Pull technology or client pull is a style of network communication where the initial request for data originates from the client, and then is responded to by the server. The reverse is known as push technology, where the server pushes data to clients.. Usually, customers will look for a site and...

, although they may appear to push

Push technology

Push technology, or server push, describes a style of Internet-based communication where the request for a given transaction is initiated by the publisher or central server...

content to the user.

The kinds of content delivered by a web feed are typically HTML

HTML

HyperText Markup Language is the predominant markup language for web pages. HTML elements are the basic building-blocks of webpages....

(webpage content) or links to webpages and other kinds of digital media. Often when websites provide web feeds to notify users of content updates, they only include summaries in the web feed rather than the full content itself.

Web feeds are operated by many news website

Website

A website, also written as Web site, web site, or simply site, is a collection of related web pages containing images, videos or other digital assets. A website is hosted on at least one web server, accessible via a network such as the Internet or a private local area network through an Internet...

s, weblogs, schools, and podcast

Podcast

A podcast is a series of digital media files that are released episodically and often downloaded through web syndication...

ers.

Benefits

Web feeds have some advantages compared to receiving frequently published content via an email:

Users do not disclose their email address when subscribing to a feed and so are not increasing their exposure to threats associated with email: spam, viruses, phishing
Phishing
Phishing is a way of attempting to acquire information such as usernames, passwords, and credit card details by masquerading as a trustworthy entity in an electronic communication. Communications purporting to be from popular social web sites, auction sites, online payment processors or IT...

, and identity theft.
Users do not have to send an unsubscribe request to stop receiving news. They simply remove the feed from their aggregator.
The feed items are automatically sorted in that each feed URL has its own sets of entries (unlike an email box where messages must be sorted by user-defined rules and pattern matching).

In its explanation "What is a web feed?", the publishing group of Nature

Nature (journal)

Nature, first published on 4 November 1869, is ranked the world's most cited interdisciplinary scientific journal by the Science Edition of the 2010 Journal Citation Reports...

describes two benefits of web feeds:

"1. It makes it easier for users to keep track of our content...This is a very convenient way of staying up to date with the content of a large number of sites."

"2. It makes it easier for other websites to link to our content. Because RSS feeds can easily be read by computers, it's also easy for webmasters to configure their sites so that the latest headlines from another site's RSS feed are embedded into their own pages, and updated automatically."

Scraping

Usually a web feed is made available by the same entity that created the content. Typically the feed comes from the same place as the website. Not all websites, however, provide a feed. Sometimes third parties will read the website and create a feed for it by scraping

Web scraping

Web scraping is a computer software technique of extracting information from websites...

it. Scraping is controversial since it distributes the content in a manner that was not chosen by the authors.

Technical definition

A web feed is a document

Document

The term document has multiple meanings in ordinary language and in scholarship. WordNet 3.1. lists four meanings :* document, written document, papers...

(often 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....

-based) whose discrete content items include web links to the source of the content. News

News

News is the communication of selected information on current events which is presented by print, broadcast, Internet, or word of mouth to a third party or mass audience.- Etymology :...

websites and blogs are common sources for web feeds, but feeds are also used to deliver structured information ranging from weather

Weather

Weather is the state of the atmosphere, to the degree that it is hot or cold, wet or dry, calm or stormy, clear or cloudy. Most weather phenomena occur in the troposphere, just below the stratosphere. Weather refers, generally, to day-to-day temperature and precipitation activity, whereas climate...

data to top-ten lists of hit tunes to search

Search engine

A search engine is an information retrieval system designed to help find information stored on a computer system. The search results are usually presented in a list and are commonly called hits. Search engines help to minimize the time required to find information and the amount of information...

results. The two main web feed formats are RSS

RSS (file format)

RSS is a family of web feed formats used to publish frequently updated works—such as blog entries, news headlines, audio, and video—in a standardized format...

and 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...

.

"Publishing a feed" and "syndication" are two of the more common terms used to describe making a feed available for an information source such as a blog. Web feed content, like syndicated print newspaper features or broadcast programs, may be shared and republished by other websites. (For that reason one popular definition of RSS is Really Simple Syndication.)

Feeds are more often subscribed to directly by users with aggregators or feed readers which combine the contents of multiple web feeds for display on a single screen or series of screens. Some modern web browsers incorporate aggregator features. Users typically subscribe to a feed by manually entering 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 a feed or clicking a link in a web browser.

Web feeds are designed to be machine-readable rather than human-readable

Human-readable

A human-readable medium or human-readable format is a representation of data or information that can be naturally read by humans.In computing, human-readable data is often encoded as ASCII or Unicode text, rather than presented in a binary representation...

, which tends to be a source of confusion when people first encounter web feeds. This means that web feeds can also be used to automatically transfer information from one website to another without any human intervention.

Confusion between Web feed and RSS

The term RSS is often used to refer to web feeds or web syndication in general, although not all feed formats are RSS. The Blogspace description of using web feeds in an aggregator, for example, is headlined "RSS info" and "RSS readers" even though its first sentence makes clear the inclusion of the Atom format: "RSS and Atom files provide news updates from a website in a simple form for your computer."

Benefits

Scraping

Technical definition

Confusion between Web feed and RSS

See also