A cookie is a text string that is included with Hypertext Transfer Protocol requests and responses. Cookies are used to maintain information as we navigate different pages on a website or return to the website at a later time. Cookies cannot be used to run code (programmes) or deliver viruses to computer. One of their primary purposes is to provide a convenience feature that one can use to save time — it tells the web server that you have returned to the page. If you personalize web pages or register for products and services, a cookie helps the page server recall your specific information, like billing address, shipping address.