Lernpfad:Web Tracking/Cookies

Cookies are the most widely known method to identify a user. They use small pieces of data (each limited to 4 KB) placed in a browser storage by the web server. When a user visits a website for the first time, a cookie file with a unique user identifier (could be randomly generated) is stored on the user’s computer.

Subsequent visits to the Facebook page do not require you to login, because your details will be remembered by the browser through a cookie stored during your first login.