Information stored on a user’s computer by a Web site so preferences are remembered on future requests.
Cookies are passed from a Web server through a Web browser to the user’s hard drive. This information is essential for many of the features taken for granted on the Web, such as shopping carts and personalized portals.
Privacy advocates have raised concerns over the role of cookies in online advertisements. They fear that large companies could piece together information which could be used against individuals, especially if offline information is merged with online information.
Cookies are not universally used. Estimates vary, but some percentage of the Web population browses with cookies turned off. Cookies can be blocked completely via the browser, or selectively via a cookie manager.