Cookies are files sent by web servers to web browsers, and stored by the web browsers.
This data is then sent back to the server every time the browser requests a page from the server. This facilitates a web server to identify and track web browsers.
Two key types of cookies are commonly used: session cookies and persistent cookies. Session cookies are deleted from your computer when you close your browser, while persistent cookies linger stored on your computer until deleted, or until they reach their expiry date.
In Internet Explorer, you can refuse all cookies by clicking “Tools”, “Internet Options”, “Privacy”, and selecting “Block all cookies” using the sliding selector.
In Firefox, you can adjust your cookies settings by clicking “Tools”, “Options” and “Privacy”.
Blocking cookies will have a negative effect upon the functionality of some websites.