Note: This page describes functionality that is not active and should not be utilized. The page is being maintained for archival purposes only.
Tags are short, simple descriptions used to organize information about places, pages, and people. The idea comes from sites like http://del.icio.us/ and http://flickr.com/ which use tags to organize links and photos. Users add a word or two ("vacation", "2005", "amita", "santa-barbara", "beach") to categorize items. Users can then search and sort items by tag ("Show me stuff tagged 'vacation' and also 'santa-barbara', so I can see pictures from my trip to Santa Barbara"), and also look at other users' images or links or whatever with the same tag.
This article describes how tags work on Wikitravel.