 browser. The identifier is then sent back to the server each time the browser requests a page from the server. Cookies may be either "persistent" cookies or "session" cookies: a persistent cookie will be stored by a web browser and will remain valid until its set expiry date, unless deleted by the user before the expiry date; a session cookie, on the other hand will expire at the end of the user session, when the web browser is closed. Cookies do not typically contain any information that personally identif