The Internet.

Introducing The Internet

The Internet: one small step for geeks, phreaks and technojunkies, one giant leap for the rest of us. We explain all.

You can't watch television without being bombarded with www.things; you can't take down @n @ddress without hitting the @ key; and you can't find a newspaper which doesn't contain the I-word. Fans enthuse about e-mail, newsgroups and the World Wide Web, but they never bother to explain what the Internet is, how it works or what you have to do to get involved. Here, then, are the answers to those questions.

What is the Internet?

The Internet is made up of five things: computers, cables, software, data (anything from words and pictures to fully formatted documents and program files) and people. The cables connect the computers together, enabling the software to move the data from one machine to the next. The people produce the data, decide where it should go and generally make things interesting.

What good is the Internet?

Take our word for it, it's grand. Ever since the Internet was invented, people have been coming up with new ways to take advantage of its ability to shift data. All you need is some idea of the services which are available – and the software to access them. FTP is one of the oldest Internet services. It enables you to move files from one computer to another (the letters stand for file transfer protocol), and it's dead useful if you like messing about with shareware or collecting picture files and sound samples. FTP software simply displays a list of the files on the remote computer, enabling you to select the ones you want to copy (or 'download') on to your computer. You can also copy files on to the other computer. .

In more technical terms, the Internet is a network of networks which connects computers from all over the world. We say 'network of networks' because most of the computers on the Internet are also part of smaller networks within companies, universities, government departments and so on. The Internet connects all these networks into a humungous global network, enabling an estimated 40 million people to access information, exchange files and communicate with one another.

What? Your computer isn't part of a network? Not to worry: you can use a modem to access the Internet. You simply dial into a computer owned by an Internet service provider, establishing a temporary connection which enables you to send and receive data down your phone line. You're only part of the Internet while you're actually connected or 'on-line,' but that's good enough for most of us.

How does it work?

Pretty much any type of computer can be connected to the Internet, be it a HAL-style supercomputer or a humble desktop model. Although these computers have very little in common and run completely different software, they can be made to work together because they both 'speak' TCP/IP, the lingua franca of the Internet.

TCP/IP, or Transmission Control Protocol/Internet Protocol if you like spelling things out, is a set of rules which determine how data is passed around the network. It was developed by the US Department of Defence (DoD) in the late 1960s, when nuclear war seemed a good deal more likely than it does today. Setting up a central control unit was clearly a daft idea (one well-placed bomb and your communications and control network is history), so the DoD designed a system in which all the computers share the responsibility for getting data from A to B. If one computer goes down, the others pick up the slack, re-routing your files via computers C, D or E.

For this to work, each computer on the Internet has to have a unique address. These addresses are called 'IP numbers', and they look something like 194.217.172.1. IP numbers aren't very easy to remember, so many of the computers also have names, such as www.futurenet.co.uk These names are automatically turned into numbers when you type them in.

Suppose you want to send a file to the computer at 194.217.172.1. The TCP part of TCP/IP breaks it into manageable chunks or 'packets' and adds the address (it also adds your address, so the receiving computer knows where the data is coming from). IP gets the packets from A to B, using any route which seems halfway sensible. The packets don't necessarily all go the same way, but they should all end up in the same place. TCP then checks that all the packets have arrived, asks the originating computer to resend any that are missing and reassembles them in the right order. All this boils down to one simple fact: TCP/IP makes the Internet work, so you have to run TCP/IP software before you can join in the fun. If you're using a modem, this usually means installing a small program which not only dials your modem and connects you to your service provider's computer, but also handles the sending and receiving of data. You can then run more specialised software to access e-mail, newsgroups, the World Wide Web and all the other Internet services.

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