Cookie: A small text file saved in your computer when you access certain Web pages. Cookies identify you to the Web site that gave you the cookie.
Digital certificate: A small file that can be transferred to your computer and used for authentication. Once installed, it can be automatically used as needed.
Internet protocol (IP) address: A string of numbers that are translated into a domain name.
Operating system: The program responsible for overseeing the basic hardware resources of a computer. UNIX, DOS, Windows, and Macintosh System 7 are examples of operating systems.
Secure server: A computer system set up to provide privacy, integrity, and authentication in communications. (See TLS/SSL).
Security protocol: A specification that describes how computers will talk securely to each other on a computer network.
TLS/SSL: Transport Layer Security (TLS) and its predecessor, Secure Sockets Layer (SSL), are cryptographic security protocols designed to provide communication security over the Internet by encrypting Internet communications.
Session ID: The code used to keep track of a person as they interact with a server.
Site certificate: This is the same as a digital certificate, but it is used on the server rather than at the browser.
128-bit encryption, 256-bit encryption: A way of making data unreadable to everyone except the receiver. It's a common way of sending credit card numbers and data over the Internet. It is used by TLS/SSL.
Web beacon: Also called a Web bug, pixel tag or clear GIF, a Web beacon is a clear graphic image placed in Web pages. Web beacons are used in conjunction with cookies to monitor user activity on a Web site.