Black hat SEO refers to a set of practices that are used to increases a site or page’s rank in search engines through means that violate the search engines’ terms of service. The term “black hat” originated in Western movies to distinguish the “bad guys” from the “good guys,” who wore white hats. Recently, it’s used more commonly to describe computer hackers, virus creators, and those who perform unethical actions with computers.
Keyword Stuffing :- Loading your website with keywords will only lead you to being penalized by search engines. It results in a negative user experience and can harm your ranking.
Doorway Pages:- Doorway pages is a black hat technique that uses “fake” pages specially for search engine spiders as a attempt to trick them into indexing sites higher.
Cloaking:- Cloaking is a technique where content as view by the user is different form that of search engines. This is another attempt to trick search engines for higher ranking.
Link Farms:- Link Farming is the act of setting fake website to promote interlinking. It is done to fool search engines into thinking your site has relevant inbound links.