A unique string of letters and numbers that the web server stores in a file on your hard drive. Cookies are used by web designers to track visitors to a web site so the visitors do not have to enter the same information every time they go to a new page or revisit a site. Cookies can keep track of personal information about an Internet user.

A method of encoding messages to provide privacy for e-mail, discussion group postings, and other communications as they move over intranets or the Internet. When you order online, online companies have used encryption to protect your credit card information, etc.