What is the Internet?

The Internet is a network of computer networks, all combining to make one super-network, passing data seamlessly from one kind of connection to another, identifying and locating indidvidual sub-networks, computers, and resources without discrimination between the different types of its member networks.

Thus, the Internet, although it functions in many ways as as a single entity, is really a collection of many separate systems; it is not run from any single operatioins centre. In this way, it's very similar to "the international telephone system", on which you can dial anyone almost anywhere in the world without having to know what kind of telephone they have or how many pieces of wire there are (if any) in the connection to their phone.

What kinds of information does the Internet carry?

Just as the telephone system carries more than one kind of information on a common carrier technology (voice and fax, for a start), the Internet carries several kinds of traffic. (New kinds can be added at any time, by agreement between the sites that are transferring it amongst themselves). Here we list some of the more widely-used kinds of network traffic.

email: email (electronic mail) sends messages from one individual to another, either directly or via a "mailing list" of people discussing a particular subject area. email addresses look like webmaster@coin.org.uk where webmaster is the name of a person (the person who writes web pages for a site is conventionally called the webmaster) and coin.org.uk is the site name (that identifies which computer to send the message to the webmaster of).
World-Wide Web: This transfers pages of information (such as this one) from the server where they're stored to the user's computer for viewing. They may contain text, pictures, little programs to make them do things, and even sounds... the system is flexible, and more types of information may be added to it at any time. A web address is called a URL (Uniform Resource Locator) and looks like http://www.coin.org.uk/technical/internet.html where http: tells your computer how to fetch the information, //www.coin.org.uk tells it which computer to use as the server to fetch the information from, and /technical/internet.html tells it which file on the fileserver it should ask it for.
Usenet: Usenet, often called "news, is similar to email, but instead of going to specified people, the messages (called "articles") are posted onto "newsgroups" (arranged by topic) which can be read on computers all over the Internet. There are thousands of newsgroups, of varying levels of specialization.
IRC: Internet Relay Chat is the text equivalent of a conference call system, in which you see all the messages typed on your selected channel as soon as they are typed.
ftp: File Transfer Protocol is the traditional way of moving files around the Internet. If you fetch a program from somewhere, this is how it will normally be fetched.

What's an ISP?

Just as you need a Telephone Service Provider (that is, a company running a telephone exchange and the associated connection system) to connect your telephone to the international telephone network, you need an Internet Service Provider (ISP) to connect your computer to the Internet. The ISP has computers with modems attached, that your computer calls via its modem. Their computers transfer data between your modem and the main network. (Some large companies are connected directly to the main network, but not many.) With the usual facilities provided by an ISP, your network address (in its various forms, for email, web pages, and so on) will appear to be part of their network (although for an extra charge, they can make your system have a network name in its own right).

Return to Technical Index

Return to Home Page Go to Top of Document

What is COIN ?

Email Lists

Resources

Technical

How to join

Constitution

Email the Webmaster