In Cheers you don't have to create categories or subcategories as people usually do, you just have to tag your assets!
Tags are markers or labels related to a topic, area of interest, a project you have, you name it ! You create the tag by actually tagging your assets that are images, documents, snippets, videos, in addition to contacts. The importance of tags is that they gather all the needed assets under one or more topic, which is one or more tag !