Photo © Corbis

Think about how many ways there are for you to communicate today. You can send a letter or a package at the post office. You can pick up the phone and make a call. You can send an e-mail. But today, one of the most popular ways to communicate is called instant messaging. In fact, you might be using instant messaging already -- lots of people love it! In any instant messaging system, you type a little text message on your computer, press the "Send" button, and your message INSTANTLY shows up on your friend's screen. But how does it work?

Actually, the whole process is very cool. First, let's look at a little history. People have been sending instant messages for a long time. In the 1980s, you could sit down at a computer at any big university. This computer would have been a UNIX machine, because it ran an operating system called UNIX. Up to 100 people would be logged in and sharing the computer. They had to share because these computers were very expensive. You could type a command to send an instant message to anyone logged into the same computer. It felt like everyone was connected together no matter where they were sitting.

Today, you can do the same thing -- but with lots more possibilities. And you can communicate with just about anyone in the world. All you need is an instant messaging program installed on your computer. There are many programs to choose from. AOL's instant messenger (AIM) is probably the most popular right now. MSN has one. Google has Google Talk. Ask your friends and find out what they are using. That will make it easier to communicate with them.

When you’re ready, you create an account. That's easy, and it only takes a couple of minutes. Next, you need to figure out the IM names your friends use. The easiest way is to ask them. Add their IM names to your IM program. Now you are ready to send a message. Click on the friend you want to talk to and then type away. When you click “Send,” your friend gets the message instantly. That's all there is to it!

But behind the scenes, amazing things are happening. Your IM program is communicating with a computer, called a server. The server could be just down the road or even in some other city. All your friend's computers are communicating with a server, too. Your computer is constantly chatting with the server to make everything happen. The network called the Internet makes it all possible.

It’s really is an amazing system. There are literally billions of machines connected to the Internet. There are millions of miles of wire and fiber optic cables and radio links connecting them all together. There are thousands of specialized computers, called routers, which make sure messages go to the right machines. Your machine does not have to worry about any of that. It just sends a message to an IP address, and a millisecond later, the message arrives at your friend's machine. You can send messages all day long, talking about homework, a big party or anything else. The messages go where they need to go automatically, anywhere in the world. That is the power of the Internet.

XFire XFire is an instant messaging program specially designed for gamers. XFire lets you send messages to your friends WHILE playing a game. More than 5 million people use XFire for PC games. Xfire is also coming to PS3 games. When you are using XFire, your friends can see that you are online (just like a normal IM program), and they can see what game you are playing. In many games, XFire makes it easy to find and login with your friends too.

Photo courtesy Xfire, Inc.