What is cloaking?

mean presenting different content or URLs to users and search engines. It may cause your site to be perceived as deceptive and removed from the Google index.

Some examples of cloaking:

Serving a page of HTML text to search engines, while showing a page of images or Flash to users.
Serving different content to search engines than to users.

If your site contains elements that aren't crawlable by search engines (such as Flash, Javascript, or images), you shouldn't provide cloaked content to search engines. Rather, you should consider visitors to your site who are unable to view these elements as well. For instance:

Provide alt text that describes images for visitors with screen readers or images turned off in their browsers.
Provide the textual contents of Javascript in a noscript tag.
Ensure that you provide the same content in both elements (for instance, provide the same text in the Javascript as in the noscript tag). Including substantially different content in the alternate element may cause Google to take action on the site.