A cookie is a piece of information in the form of a very small text file that is placed on an internet user’s hard drive. It is generated by a web page server, which is basically the computer that operates a web site. The information the cookie contains is set by the server and it can be used by that server whenever the user visits the site. A cookie can be thought of as an internet user’s identification card, which tell a web site when the user has returned.
Cookies are not computer programs, and they can’t be executed as code. Also, they cannot be used to disseminate viruses, and modern versions of both Microsoft Internet Explorer and Netscape browsers allow users to set their own limitations to the number of cookies saved on their hard drives.
Cookies are stored on the computer’s hard drive. They cannot access the hard drive, so a cookie can’t read other information saved on the hard drive, or get a user’s e-mail address etc. They only contain and transfer to the server as much information as the users themselves have disclosed to a certain web site.