All cookies have expiration dates that determine how long they stay in your browser: Session Cookies – these are temporary cookies that are placed on your device during your browsing session and then expire (and are automatically erased) whenever you close your browser. Persistent Cookies – these are designed to last for a pre-defined period of time, which varies depending on the nature of the cookie. Persistent cookies stay in your browser until they reach their individual expiry date, or until you manually delete them (See Section 5 below).