What is a cookie?
A cookie is a small amount of data, which often includes an anonymous unique identifier that is sent to your browser from a website's computer and stored on your computer's hard drive. Each website can send its own cookie to your browser if your browser's preferences allow it, but (to protect your privacy) your browser only permits a web site to access the cookies it has already sent to you, not the cookies sent to you by other sites.
Many sites do this whenever a user visits their website in order to track online traffic flows.
Cookies record information about your online preferences. Users have the opportunity to set their computers to accept all cookies, to notify them when a cookie is issued, or not to receive cookies at any time.
Each browser is different, so check the "Help" menu of your browser to learn how to change your cookie preferences.