Use this tag for questions about guidance using the appropriate tags, or questions proposing tag cleanup, such as new tags, tag synonyms or deleting certain tags.

From the help-center:

A tag is a word or phrase that describes the topic of the question. Tags are a means of connecting experts with questions they will be able to answer by sorting questions into specific, well-defined categories.

Tags can also be used to help you identify questions that are interesting or relevant to you.