Term: "Cloaking"

Cloaking is the presentation of alternate pages to a search engine Spider to crawl so that it will index different content for that URL to what a human browser would view. This practice is a carried out to help achieve a higher search engine position or to deceive users into visiting a site they had no intention of visiting. This is considered to be Black Hat SEO and the culprits URL is more than likely to be blacklisted. Sometimes cloaking is used to convey personalized content based on the browser's IP address. This form of cloaking should only be practiced after the search engines have been made aware so as to prevent any blacklisting.