Cookie
Information placed on a visitor’s computer or Mobile handset by a Web server that can be stored or retrieved when the site is accessed. Cookies are generally used as unique identifiers (i.e. user IDs or session IDs) to record a users unique behavior during each visit. Cookies may be used to store other data such as email address, usernames etc. Most mobile handsets do not support cookies, although the market long-term is moving in this direction.