SEO is short for Search Engine Optimization. Search Engine Optimization refers to how you are ensuring that search engines can find your site. Search engines are based on text searches. They send out bots or spiders (not really a robot or spider–it’s an algorithm) that crawl your pages and send back information based on the text it finds. To optimize the report from your blog, you need to have the most relevant text or search terms for a query.
We have several articles at Blogging Basics 101 that can help you with this: