Cookie

A special text file that a Web site puts on your hard disk so that it can remember something about you at a later time. Typically, a cookie records your preferences when using a particular site. Using the Web's Hypertext Transfer Protocol (HTTP), each request for a Web page is independent of all other requests. For this reason, the Web page server has no memory of what pages it has sent to a user previously or anything about your previous visits. A cookie is a mechanism that allows the server to store its own file about a user on the user's own computer. The file is stored in a subdirectory of the browser directory (for example, as a subdirectory under the Netscape directory). The cookie subdirectory will contain a cookie file for each Web site you've been to that uses cookies.

Cookies are commonly used to rotate the banner ads that a site sends so that it doesn't keep sending the same ad as it sends you a succession of requested pages. They can also be used to customize the pages they send you based on your browser type or other information you may have provided the Web site. Web users must agree to let cookies be saved for them, but, in general, it helps Web sites to serve users better.