White Hat SEO
White Hat SEO is the process to increase the visibility of the website in the SERP (search engine result page) in a natural or organic (un-paid) way.
Unpaid , Natural or organic way is, when we follow search engines guidelines and policies to generate backlinks.
Black Hat SEO:-
Black hat SEO refers to the usage of techniques and strategies used to increase the traffic on the website by doing spam activities and don’t focus upon the human audience. Black hat SEO don’t obey to the rules, policies and guidelines provided by the search engines. Some examples of black hat seo techniques are sneaky redirect, keyword stuffing, doorways pages, cloaking, paid links etc.