It is White Hat and Black Hat SEO not a "Cat" just search white hat seo or black hat seo in any search engine you easily found lots of defination available.
White Hat SEO is things that the search engines would approve of, like having a great site with original content, naturally building links, etc. Black Hat SEO is sneaky ways to trick the search engines, like buying links and keyword stuffing. In general, the search engines want to help their customers find the best sites that are the best match for what they're looking for so they'll continue to use their search engine. Anything in keeping with that goal is white hat seo. Anything trying to thwart that goal is black hat.