Cookies

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 tells a web site when the user has returned.
Cookies make the interaction between users and web sites faster and easier. Without cookies, it would be very difficult for a web site to allow a visitor to fill up a shopping cart or to remember the user's preferences or registration details for a future visit.
There are two main types of cookies:
· Session, or transient cookies: Cookies that are stored in the computer's memory only during a user's browsing session and are automatically deleted from the user's computer when the browser is closed. These cookies usually store a session ID that is not personally identifiable to users, allowing the user to move from page to page without having to log-in repeatedly. They are widely used by commercial web sites (for example, to keep track of items that a consumer has added to a shopping cart). Session cookies are never written on the hard drive and they do not collect any information from the user's computer. Session cookies expire at the end of the user's browser session and can also become no longer accessible after the session has been inactive for a specified length of time, usually 20 minutes.
· Permanent, persistent, or stored cookies: Cookies that are stored on the user's computer and are not deleted when the browser is closed. Permanent cookies can retain user preferences for a particular web site, allowing those preferences to be used in future browsing sessions. Permanent cookies can be used to identify individual users, so they may be used by web sites to analyze users' surfing behavior within the web site. They are usually configured to keep track of users for a prolonged period of time, in some cases many years into the future.

Cookies are not computer programs. They cannot be used to disseminate viruses.