A cookie is a small file that is transmitted by web servers to web browsers, and may be returned to the server whenever a request is made via the browser.
Cookies are often used by websites to identify returning users and track navigation of the website, providing useful functionality such as shopping carts and statistics to improve usability.
There are two types of cookies, persistent and session. A persistent cookie will remain on your computer until it's expiry date or it is a deleted. A session cookie works slightly differently, a session cookie only remains on your computer until the web browser is closed.
Cookies and this website
Blocking cookies will have a negative impact upon the usability of many websites.
Cookies already stored on your computer can be deleted: