One of the largest newbie mistakes made by people first trying out search engine optimization on their websites is to try and cloak it. Most people do not even realize that they are practicing cloaking when they do it and even perceive it as a legitimate form of SEO but the problem is that the big search engines will penalize and blacklist your site for doing it.
In a nutshell, cloaking is the practice of using keywords and metatags to show a search engine spider a different page then what your human visitor to your site is going to see. The purpose of doing this is to drive visitors to a site. An example would be a psychic site that uses the name of famous psychics such Sylvia Browne or John Edwards to promote its services even though they sell no books or services by those famous psychics who have high keyword popularity. Some high-ranking pages are cloaked simply to prevent others from stealing the underlying code but this is no longer such a problem as it is not just keyword content or metatags that the search engine algorithms look at nowdays when they go to index a site.
Using search terms in this phony way can put your site immediately at risk of being removed promptly from the Internet by a search engine. Search engines are becoming increasingly cognizant of the techniques used to try fool them, and they are also becoming better at detecting and removing pages that violate their terms of service. This is why it is also important to be careful of any kind of SEO service in case it is using a process such as "cloaking" to boost your site in the page rankings.
Underhanded tactics such as cloaking only work until the search engines catch you.