When most people talk about "the Internet" what they are really referring to is the World Wide Web. The Internet is actually composed of many different components. Some of the components are widely known, such as FTP, while others are not so familiar, such as Gopher and Telnet.
Several protocols are used on the Internet, including Electronic Mail (e-mail), File Transfer Protocol (FTP), HTTP (World Wide Web), News (or Usenet), Gopher and Telnet. Each of these has its own standard and usage.
Included in the email protocol are three distinct protocols. SMTP (Simple Mail Transfer Protocol), IMAP (Internet Message Access Protocol) and POP3 (Post Office Protocol 3).
SMTP is a protocol used for sending mail, while IMAP and POP3 are used for receiving. Almost all Internet service providers support all three protocols. However the most popular setup for most providers is to use SMTP for sending mail while using POP3 for receiving.
File Transfer Protocol
File Transfer Protocol, or FTP, is a means of transferring a file from one computer to another. FTP is commonly used for uploading a web page to a web server so that it may be seen on the World Wide Web. A special program, called a client, is usually needed to use FTP.
HTTP (World Wide Web)
HyperText Transfer Protocol, or HTTP, is the protocol used by web server to allow web pages to be shown in a web browser. If you look up into the address bar of your web browser, the place where you type in the address that you want to visit, it has the prefix "http://" in front of the address. Because most web browsers are capable of FTP as well as viewing web pages, the http tells the browser what kind of information to expect.
News (or Usenet)
Network News Transfer Protocol (NNTP) is used for serving Usenet posts Usenet is similar to the forums that many web sites have. Usenet has forums that are dedicated to specific companies as well as forums that have a wide range of topics. Usenet is divided into several areas. Some of the forums that are included in Usenet are comp. for discussion of computer-related topics, sci. for discussion of scientific subjects, rec. for discussion of recreational activities (e.g. games and hobbies) and talk. for discussion of contentious issues such as religion and politics.
Another tool of the Internet is Gopher, a menu-based program that enables you to browse for information without knowing where the material is located. It lets you search a list of resources and then sends the material to you.
Telnet lets you log in to a remote computer just as you would if you were there. So any commands that you would be able to run from the remote computer if you were sitting in front of it, you would be able to run from the computer you logged in from.