Cookies are small pieces of information that are temporarily stored on your computer (or other internet enabled devices) when you visit a website. A cookie will usually contain the name of the website from which the cookie has come from, the "lifetime" of the cookie (i.e. how long it will remain on your device), and a value, which is usually a randomly generated unique number.
Your Internet browser should have settings, which allow you to control the placement of cookies on your computer or device. You can change the settings to allow or block the storage of cookies. Alternatively, you can adjust your browser settings to provide alerts when a cookie is being sent for storage on your computer or device. Please refer to your Internet browsers manual or help function for more information on adjusting the settings of your specific browser.