Cookies are pieces of information that a website transfers to your hard drive to store and sometimes track information about you. Most web browsers automatically accept cookies, but if you prefer, you can change your browser to prevent that. However, you may not be able to take full advantage of a website if you do so. Cookies are specific to the server that created them and cannot be accessed by other servers, which means they cannot be used to track your movements around the web. Although they do identify a user's computer, cookies do not personally identify users and passwords and credit card information are not stored in cookies.
For more information on cookies and how to disable them you can consult the information provided by the Interactive Advertising Bureau UK at www.allaboutcookies.org