raymondcc - 3:23 am on Jan 13, 2013 (gmt 0)

From Google Webmaster Tools Help:

Cloaking refers to the practice of presenting different content or URLs to human users and search engines.

- Serving a page of HTML text to search engines, while showing a page of images or Flash to users
- Inserting text or keywords into a page only when the User-agent requesting the page is a search engine, not a human visitor