A cookie is a small text file that a website can send to your computer's browser. It's like an internet user's identification card, which tells a website when a user is re-visiting the site. Cookies are helpful to provide a more personalised service. Cookies ability is limited to containing and transferring to the website as much information as the users have disclosed to that site. Cookies can't read or interfere with other information saved on your hard drive. The cathtatecards website (in common with most other shopping websites) will not work without cookies.