I hear this so often: “Should my WordPress Tags and Categories match up to my SEO keywords?”
The answer is that the process is pretty organic– naturally some of your keywords and phrases will flow into becoming part of your Categories and Tags. The goal of getting found in the Google search engine is to have the search engine finding real keywords in your text so that people are finding your website or blog in answer to their search. Search engines help people find what interests them on the web. Your blog categories and tags should also help people find what interests them.
So in many cases — keywords, categories, and tags will be the same words and perform the same function — they bring people to what you want them to find.
Will your blog Categories and Tags be form your list of keywords? In many cases… YES.