White hat SEO is the way by which you optimize using all the SEO tactics considered ETHICAL and honest in order to achieve good SERPS. It often takes a lot of time and can be time consuming. But results will help give your site prestige in addition to great placement.
Grey hat is just the combination of both white hat and black hat SEO tactics.
Simply put - white hat SEO relies on original, quality content and follows the rules while black hat techniques are any methods that go against Google's guidelines. That's the black and white, cut and dried explanation - but we all know there are gray areas in between. Some webmasters have successfully pushed those shady areas between black and white and benefited from the results, but just as many have learned the hard way that tempting the engines doesn't pay.
White hat SEO is the way by which you optimize using all the SEO tactics considered ethical and honest in order to achieve good SERPS.
Black hat SEO is the process by which you achieve SERPS placement using tactics that are completely unethical. The results are immediate but will not last.
Grey hat is just the combination of both white hat and black hat SEO tactics.
White hat SEO is considered ethical SEO, while black hat SEO is considered unethical SEO. Gray hat SEO walks the line between the white and black hats of search engine optimization.
Black hat seo is unethical seo to get your site on the top,and the second one White hat seo is the ethical and this is the proper channel and the grey hat seo is the combination of black and whitehat SEO.