You’ve likely been hearing quite a bit about tagging lately. If you’re not sure what that actually is, here’s a great article that gives a wonderful overview.
Tagging is a non-hierarchal (for hierarchies think of the old Yahoo! directories) means of organizing information or objects on the web. Information is found through associative correlations or inference. In a hierarchy one would go to people, then film, and then actress to find Cate Blanchett. Using tagging one could use actress and moviestar to get a similar result. Prior to computing hierarchies were an efficient means of organizing information. With computing we have more options, which can work just as well.
Much more info in the article.
