Social bookmarking is a method for internet users to find, organize, store, and manage bookmarks of resources online. Many online bookmark management services have launched since 1996; Delicious, founded in 2003, popularized the terms "social bookmarking" and "tagging". Tagging is an important function of social bookmarking systems, allowing users to organize their bookmarks in flexible ways and shared vocabularies known as folksonomies develop.

Descriptions can be added to these bookmarks in the form of metadata, so users can understand the contents of the resource without first to download it for them. Such descriptions may be free text comment, votes in favor of or against its quality or tags that become a collective Folksonomy. Folksonomy is an abbreviation for social tagging, "the process of which many users add metadata in the form of keywords to shared content"

In a social bookmarking system, users save links to Web pages that they want to remember and/or share. These bookmarks are usually public, and can be saved privately, shared only with specified people or groups, shared only inside certain networks, or another combination of public and private domains. The allowed people mostly find these bookmarks chronologically, by category or tags, or via a search engine.

Most social bookmark services encourage users to organize their bookmarks with informal tags instead of the traditional browser-based system of folders, although some services feature categories/folders or a combination of folders and tags. They can also view bookmarks that are associated with a chosen tag and contain information about the number of users that have bookmarked them. Some social bookmarking services also draw inferences from the relationship of tags to create clusters of tags or bookmarks.

Many social bookmarking services offer web feeds for their lists of bookmarks, including lists organized by tags. These subscribers become aware of new bookmarks as they are saved, shared, and tagged by other users.

If these services have matured and grown more popular, they have added extra features such as ratings and comments on bookmarks, the ability to import and export bookmarks from browsers, emailing of bookmarks, web annotation, and groups or other social network features.