Without cookies, websites and their servers have no memory. A cookie, like a key, enables swift passage from one place to the next. Without a cookie every time you open a new web page the server where that page is stored will treat you like a completely new visitor.

Websites typically use session cookies to ensure that you are recognized when you move from page to page within one site and that any information you have entered is remembered. For example, if an e-commerce site did not use session cookies then items placed in a shopping basket would disappear by the time you reach the checkout. You can choose to accept session cookies by changing the settings in your browser.