Cloaking

Loosely defined, is the practice of showing a search engine spider a different page than what an actual human visitor sees. This means that the server of a cloaked page makes a note of the unique address assigned to each visitor, and when that visitor is a spider, it feeds it specialized content that is designed to rank highly for certain search terms. Virtually every major engine now imposes harsh penalties on sites that use cloaking. Unfortunately, the intent of cloaking isn't always necessarily to trick search engines. Some high-ranking pages are cloaked simply to prevent others from stealing the underlying code. In any case, the practice of cloaking, for whatever reason, puts your site at risk of being penalized or removed from major engines.