ISDN A type of high speed phone line. To the layman, ISDN looks just like a regular phone line. The wiring looks the same, the bills look about the same, and the charges are billed in about the same way. ISDN merely uses a different technology than your regular phone line. A piece of equipment that changes the signals from your computer into noises that can travel over regular phone lines.
POP normally supports one mailbox per person or account.
PPP is the most common method that individuals use to connect to the Internet. The global, interconnected collection of hypertext pages. The World Wide Web consists of many multimedia pages with sounds, graphics, and text that also contains links. Generally, when you click on a link, you will be referred to another page. If you tried to draw a map of these pages and links, the result would look similar to an enormous spider web, hence the name World Wide Web.