In computing, a cookie (also browser cookie, computer cookie, tracking cookie, web cookie, internet cookie, and HTTP cookie) is a small string of text stored on a user's computer by a web browser. A cookie consists of one or more name-value pairs containing bits of information such as user preferences, shopping cart contents, the identifier for a server-based session, or other data used by websites.
Cookies are subject to a number of misconceptions, mostly based on the erroneous notion that they are computer programs that run on a user's computer. In fact, cookies are simple pieces of text data that affect the operation of a web server, not the client, and do so in very specific ways. In particular, they are neither spyware nor viruses, although cookies from certain sites are described as spyware by many anti-spyware products because they can allow users to be tracked when they visit various sites.