Black hat SEO
Black hat SEO refers to the use of aggressive SEO techniques that focus on search engines and not the human audience and these strategies usually do not obey the guidelines of search engines.
Some practices of black hat SEO include doorway pages, keyword stuffing, adding unrelated keywords to the page content, invisible text or changing the webpage entirely after it has been ranked by search engines, also known as page swapping.
Black Hat SEO will possibly result in your Web site being penalized or banned from a search engine and cannot be considered a long term investment. It is more frequently used by those who are looking for a quick financial return. Most experts use Black Hat SEO since the focus is usually on quick high return business models and consider being banned from search engines an irrelevant risk. Black Hat SEO is and always should be considered as unethical.