Cookies are based on a two-stage process.
First the cookie is stored in the user's computer without their consent or knowledge.
For example, with customizable Web search engines like My Yahoo!, a user selects categories of interest from the Web page. The Web server then creates a specific cookie, which is essentially a tagged string of text containing the user's preferences, and it transmits this cookie to the user's computer. The user's Web browser, if cookie-savvy, receives the cookie and stores it in a special file called a cookie list.
This happens without any notification or user consent.
As a result, personal information (in this case the user's category preferences) is formatted by the Web server, transmitted, and saved by the user's computer.
During the second stage, the cookie is 'clandestinely and automatically' transferred from the user's machine to a Web server. Whenever a user directs her Web browser to display a certain Web page from the server, the browser will, without the user's knowledge, transmit the cookie containing personal information to the Web server.