<h1>Tagging</h1>

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A tag is a (relevant) keyword or term associated with or assigned to a piece of information (like picture, article, or video clip), thus describing the item and enabling keyword-based classification of information it is applied to.
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<p>
Tags are usually chosen informally and personally by the author/creator of the item &mdash; i.e. not usually as part of some formally defined classification scheme. Tags are typically used in dynamic, flexible, automatically generated internet taxonomies for online 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, &quot;tagging&quot; has become associated with the Web 2.0 buzz.
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<p>
Typically, an item will have one or more &quot;tags&quot; associated with it, as part of some classification software or system. The software will provide links to other items that share that keyword tag, or even to specified collections of tags. This allows for multiple &quot;browse-able paths&quot; through the items which can quickly and easily be altered by the collection's administrator, with minimal effort and planning.
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<a href="http://en.wikipedia.org/wiki/Tag_%28metadata%29">From Wikipedia</a>