What are Tags?

Tags are used to help organize site content in simple terms. What makes Tags different from normal classification systems is that site users decide which data should be classified under which category.

From Wikipedia's article on tags:

A tag is a (relevant) keyword or term associated with or assigned to a piece of information (a picture, a geographic map, a blog entry, a video clip etc.), thus describing the item and enabling keyword-based classification and search of information.
Tags are usually chosen informally and personally by item author/creator or by its consumer/viewers/community. Tags are typically used for resources such as computer files, web pages, digital images, and internet bookmarks (both in social bookmarking services, and in the current generation of web browsers - see Flock). For this reason, "tagging" has become associated with the Web 2.0 buzz. Many people associate "tagging" with the idea of the semantic web, however some believe that tagging may not be having a positive effect on the overall drive towards the semantic web.
Typically, an item will have one or more tags associated with it.

To the right you'll see a picture of site tags on the SCI Woburn website. The more frequently a tag is chosen, the larger the term will appear in the "tag cloud."