Cookies are usually small text files, given ID tags that are stored on your computer’s browser directory or program data subfolders. Cookies are created when you use your browser to visit a website that uses cookies to keep track of your movements within the site, help you resume where you left off, remember your registered login, theme selection, preferences, and other customization functions.The website stores a corresponding file(with same ID tag)to the one they set in your browser and in this file they can track and keep information on your movements within the site and any information you may have voluntarily given while visiting the website, such as email address.

Cookie files are automatically lodged into the cookie file – the memory of your browser – and each one typically contains:

  • The name of the server the cookie was sent from
  • The lifetime of the cookie
  • A value – usually a randomly generated unique number

Types of cookies:

  • Session cookie
  • Persistent cookie
  • Secure cookie
  • HttpOnly cookie
  • Third-party cookie
  • Supercookie
  • Zombie cookie

How browsers control cookies

All major browsers provide security controls for cookies. Generally these allow users to choose to block all cookies, to only allow specific cookies, or to block third party cookies.

The official standards for cookies (RFC 2109 and RFC 2965) say that by default browsers should block third party cookies. However almost all browsers permit them, as long as the website setting the cookie has a P3P privacy policy installed, which is a simple system for stating what your website’s privacy policy is. In reality, a P3P policy can be empty or unused, allowing third party cookies regardless.