A controversial search engine ranking technique of presenting one version of a web page to search engine spiders that is specifically optimized for keywords, while returning a different version of the same page to a human user.
 
A cloaking system uses IP address attributes to identify visitors as either human or robot. Once it detects that a visitor is a robot, the cloaking system presents text only, keyword-rich pages. Some unscrupulous web masters use this technique to blatantly mislead search engine users to their sites.
 
Search engines officially frown on cloaking because of the potential for abuse and they may remove sites practicing it from their indices. Most search ranking experts will recommend you avoid this high-risk tactic for capturing traffic. There are plenty of clean ways to bring swarms of traffic to your site.