Black Hat SEO is a term used to describe a set of techniques, rules and methods for optimising and positioning websites that do not comply with the regulations of the relevant search engine. Use of Black Hat techniques SEO is very risky. Because by doing so, you risk removing your website from the search results altogether. Moreover, even if this does not happen, it is likely to its position will decline. A positioning of this site in the future will be much more difficult.
The opposite of Black Hat SEO is White Hat SEO.