This document first appeared as the packet for a seminar I taught for Glorieta Student Week, Christianity and the Internet. I've also created a version which doesn't break the document into sections, which is more suitable for printing or for those who just like to read straight through without having to click around. Thanks for dropping by.

The Internet in a Nutshell

"What is the Internet?" This question has been asked and answered more times than I can count. But I guess I'm going to try to answer it again.

The Internet

The "Internet" collectively refers to all the computers in the world which are physically connected to one another and communicate using TCP/IP.

Physically Connected?

Yes, it works like this:

Your computer, say in your home, is connected through the phone line to another larger computer. This computer belongs to your "internet service provider" or "ISP". Their computer is physically connected, using probably a huge wad of fiber-optic cable, to many other large computers (called "routers"), which are in turn connected to other routers. Another user may be connected through a large "server" in his office. In this way, any piece of information can be transferred from one small computer to another, assuming it can find its way from one end to the other.

TCP/IP?

"TCP/IP" refers to two complementary sets of protocols which provide rules for moving information across the Internet, TCP and IP. TCP, the Transport Control Protocol, handles things like making sure that a bit of information makes it across the Internet in one piece and without any errors. IP, the Internet Protocol, mostly handles physically getting the information from one end to the other; it allows the information to find its way to its destination.

Several years ago, the government, working through the Advanced Research Projects Agency (ARPA), began funding research into the best way to allow connected computers to communicate with one another. Technology resulting from this funding included a set of conventions for interconnecting networks and routing traffic. This "suite of protocols" is TCP/IP. From the average user's point of view, TCP/IP appears as a set of programs that use the network to carry out useful tasks.

By the way, TCP/IP is pronounced by simply spelling it out: "Tee-See-Pee-Eye-Pee".

Basic Function of the Internet

The Internet allows information to pass from one computer to another. Period. However, that information can come in a variety of sizes. The two extremes are characters and files.

Files

Entire files are the most common form of traffic on the Internet, and include just about anything that one would want to send. FTP, email, and the Web all transfer entire files at once.

Characters

Some applications, on the other hand, send single keystrokes at a time. This allows you to use another machine just like you use your own, sending keypresses one at a time over the Internet. Telnet is the most common application to use the Internet in this way.

Other

Finally, many applications send bits of information which are just a few words long; perhaps too short to be considered a whole file, but consisting of several characters. For example, when you click on a link on a web page, your computer sends a request out on the Internet for the new page (more on this later). This request is usually no longer than a few dozen characters, and falls into the last category for Internet traffic.

Introduction · Uses of the Internet · Getting On the Net · What To Do With It · Recommended Reading