Black hat seo techniques help to rank your keywords faster in search engines and generates more traffic in shorter time. But the methods followed are not supported by Google and hence your website can get penalized for following such techniques.
Black Hat SEO can possibly result in your Web site being banned from a search engine, however since the focus is usually on quick high return business models, most experts who use Black Hat SEO tactics consider being banned from search engines a somewhat irrelevant risk. Black Hat SEO may also be referred to as Unethical SEO or just spamdexing, as spamdexing is a typical frequently used Black Hat SEO practice.
Black hat seo does not follow guide line of search engine. Black hat seo techniques are Cloaking, Doorway pages, Keyword stuffing, Link Farming, Tiny URL, Spam blogs etc.
Black hat SEO does not follow the search engine guidelines and thus allows the search engine to rank down your website on the SERP or even ban your website, depending on how serious your activity has been.