White hat SEO: It is one of the most popular SEO technique Which is only optimized for rules and regulations of search engines. Black hat SEO: Blackhat SEO, on the other hand, is a type of an SEO technique which exploits the various weaknesses in the algorithms or search engines in order to get high rankings for websites. This may be a problem anytime if any new algorithm were released. Grey SEO: This kind of a SEO is a kind of a SEO which is neither black nor white. This is a technique that does not fully use the black hat SEO and rather combines both. They may not cross the line to black hat SEO.