Folksonomies are created by users trying to identify Web content by assigning their own keywords called tags. There is no hierarchical structure or controlled vocabulary. Folksonomies are created by anyone interested in assigning tags to something online, and collectively all the tags create the folksonomy. Because folksonomies are created by users, the terms assigned as tags are likely to be common parlance and often terms that appear in the actual document. There is, however, a possibility of many different tags describing the same things or a single tag referring to more than one thing, creating problems with precision and recall. Folksonomies and tagging are commonplace in social media applications such as blogs, social bookmarking, Flickr, etc.