A:
Think of a tag as a category name. People can categorize their posts, blog, photos, videos, or music with any tag that makes sense to describe it. In Technorati, there are two kinds of tags. There is the Post Tag and the Blog Tag.
The Post Tag is used to describe the topics covered in individual items and is associated to the item either via Tag Code or Category Code (Wordpress Categories, Blogger Labels). This can apply to all types of media such as posts, photos, videos, or music. The tags list the item in the Tag Search pages. For information on post tags and how to create them, you can go to http://support.technorati.com/support/siteguide/tags
Blog Tags are assigned from the Technorati account blog setting for each successfully claimed blog and are used to describe the topics the blogs covers. It also lists the claimed blog in the Blog Directory under each Blog Tag. For information on blog tags and how to create them, you can go to http://support.technorati.com/support/siteguide/directory