Cookies are text files which are downloaded to your personal computer, mobile or other device when you visit a website. Cookies are then sent back to the originating website on each subsequent visit, or to another website that recognises that cookie. Cookies are useful to allow a website to recognise a user's device.
Cookies perform a number of functions, including letting you navigate between pages efficiently, remembering your preferences, and generally improving the user experience. They can also be used to ensure that adverts you see online are more relevant to you and your interests.