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.
 Tags are usually chosen informally and personally by the author/creator or the consumer of the item — 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.

What does a TagCloud look like?

 It's a list of keywords taken from the news feeds you specify. Larger fonts indicate a higher prevalence for an individual keyword. Using Cascading Style Sheets, you can customize almost every aspect of your TagClouds to make it match your website.

 Tags Website: