A folksonomy is a system of classification derived from the practice and method of collaboratively creating and managing tags

Tag (metadata)

In online computer systems terminology, a tag is a non-hierarchical keyword or term assigned to a piece of information . This kind of metadata helps describe an item and allows it to be found again by browsing or searching...

 to annotate and categorize

Categorization

Categorization is the process in which ideas and objects are recognized, differentiated and understood. Categorization implies that objects are grouped into categories, usually for some specific purpose. Ideally, a category illuminates a relationship between the subjects and objects of knowledge...

 content

Content (media and publishing)

In media production and publishing, content is information and experiences that may provide value for an end-user/audience in specific contexts. Content may be delivered via any medium such as the internet, television, and audio CDs, as well as live events such as conferences and stage performances...

; this practice is also known as collaborative tagging, social classification, social indexing, and social tagging. Folksonomy, a term coined by Thomas Vander Wal

Thomas Vander Wal

Thomas Vander Wal is an information architect best known for coining the term "folksonomy". He is also known for initiating the term "infocloud"...

, is a portmanteau of folk

Folk

The English word Folk is derived from a Germanic noun, *fulka meaning "people" or "army"...

and taxonomy

Taxonomy

Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...

.

Folksonomies became popular on the Web

World Wide Web

The World Wide Web is a system of interlinked hypertext documents accessed via the Internet...

 around 2004 as part of social software

Social software

Social software applications include communication tools and interactive tools. Communication tools typically handle the capturing, storing and presentation of communication, usually written but increasingly including audio and video as well. Interactive tools handle mediated interactions between a...

 applications such as social bookmarking

Social bookmarking

Social bookmarking is a method for Internet users to organize, store, manage and search for bookmarks of resources online. Unlike file sharing, the resources themselves aren't shared, merely bookmarks that reference them....

 and photograph annotation.