Cache
A memory area where frequently accessed data can be stored for rapid access.

Camera Ready
Document or image ready for print

CD
compact disc for data storage

Click-rate
Percentage of users who click on a viewed advertisement.

Clicks
The opportunity for a visitor to be transferred to a location by clicking on an ad (see click through).

Click-through
The action of following a hyperlink within an ad.

Cookie
A tracer which is attached by the receiving server to a browser used by a visitor. It identifies the computer and tracks the behavior of all users of that computer within a particular site.

Crawler-based search engines
Engines that use automated software to index the billions of files online.

CSS
Cascading Style Sheets. Language used to describe how an HTML document should be formatted.

CSV
A file with Comma Separated Values