In this part …

One day the Network Thugs barge into your office and shove a gun in your face. "Don't move until we hook you up to the network!" one of them says while the other one connects one end of a suspicious-looking cable to the back of your computer and shoves the other end into a hole in the wall. "It's done," they say as they start to leave. "Now, don't you say nuttin to nobody-or we'll be back!"

If this has happened to you, you'll appreciate the chapters in this part. They provide a gentle introduction to computer networks written especially for the reluctant network user .

What if you don't have a network yet and you're the one who's supposed to do the installing? Then the chapters in this part clue you in to what a network is all about. That way, you're prepared for the ( unfortunately more technical) chapters in Part II and beyond.

Chapter 1: Networks Will Not Take Over the World, and Other Network Basics

Computer networks get a bad rap in the movies. In the Terminator movies, Skynet (a computer network of the future) takes over the planet, builds deadly terminator robots, and sends them back through time to kill everyone unfortunate enough to have the name Sarah Connor. In The Matrix movies, a vast and powerful computer network enslaves humans and keeps them trapped in a simulation of the real world. And in one of Matthew Broderick's first movies, War Games, a computer whiz kid nearly starts World War III by connecting to a Defense Department network and playing the game Global Thermonuclear War.

Fear not. These bad networks exist only in the dreams of science fiction writers. Real-world networks are much more calm and predictable. They don't think for themselves , they can't evolve into something you don't want them to be, and they won't hurt you-even if your name is Sarah Connor.

Now that you're over your fear of networks, you're ready to breeze through this chapter. It's a gentle, even superficial, introduction to computer networks, with a slant toward the concepts that can help you use a computer that's attached to a network. This chapter goes easy on the details; the detailed and boring stuff comes later.

What Is a Network?

A network is nothing more than two or more computers connected by a cable (or in some cases by radio connection) so that they can exchange information.

Of course, computers can exchange information in ways other than networks. Most of us have used what computer nerds call the sneakernet. That's where you copy a file to a diskette, a CD-RW disc, or a removable flash drive, and then walk the data over to someone else's computer. (The term sneakernet is typical of computer nerds' feeble attempts at humor, and why not? As a way to transfer information, sneakernet is feeble.)

The whole problem with the sneakernet is that it's slow-plus, it wears a trail in your carpet. One day, some penny-pinching computer geeks discovered that connecting computers with cables was cheaper than replacing the carpet every six months. Thus, the modern computer network was born.

You can create a computer network by hooking together all the computers in your office with cables and using the computer's network interface (an electronic circuit that resides inside your computer and has a special jack on the computer's backside ). Then you set up your computer's operating system software to make the network work, and- voil -you have a working network. That's all there is to it.

If you don't want to mess with cables, you can create a wireless network instead. In a wireless network, each computer is equipped with a special wireless network adapter that has little rabbit-ear antennas. Thus, the computers can communicate with each other without the need for cables.

Figure 1-1 shows a typical network with four computers. You can see that all four computers are connected by a network cable to a central network device: the hub. You can also see that Ward's computer has a fancy laser printer attached to it. Because of the network, June, Wally, and the Beaver can also use this laser printer. (Also, you can see that the Beaver stuck yesterday 's bubble gum to the back of his computer. Although the bubble gum isn't recommended, it shouldn't adversely affect the network.)

Figure 1-1: A typical network.