Cookies are unique identifiers that a Web server places on your computer when you visit a particular site. The cookies (files) store information about the pages you visit and the information you view. The cookies can then be used to retrieve your records from the vendors� databases, and that information can be used without your consent. Any Web site that knows your identity and has a cookie for you can set up procedures to exchange their data with companies that buy advertising space from them. You can turn off or delete the cookies on your computer, but be aware that doing so means you will have to re-enter personal information when shopping online, and you won�t be able to have any personal accounts with such sites as Yahoo!.