Cloaking is a search engine optimization (SEO) technique in which the content presented to the search engine spider is different from that presented to the user's browser. This is done by delivering content based on the IP addresses or the User-Agent HTTP header of the user requesting the page.
Cloaking is one of the unethical practices in SEO. It uses the devices that provide deceiving mechanism for the search engines.Cloaking provides the use of false pages that are loaded with the keyword, invisible keywords in content and other content that is search engine optimized.
Cloaking is the Black Hat SEO in which content is hide on the webpage. Actually that is not for visitor. Search Engine Crawler will be crawl and provide the result as the requirement is the main Purpose.
Clocking is a technique in which the content of a website presented to the search engine crawler is different from the users of it. It can be called as a black hat SEO technique.