Introducing UNIX and Linux

UNIX and Linux Design and Organisation

Overview
The Kernel and Shell
Files
      Networks
Technical Basics
      Bits, Bytes, Words and Characters
      ASCII Characters
How to get Linux
Summary

Networks

Computer systems contain at least one computer. However, it is becoming increasingly difficult to define what is meant by 'a computer' - until a few years ago, a computer would have had a single CPU. which would perform all the computational tasks.

Nowadays, a computer may contain several processing units around which the workload will be distributed. In addition, several computers may be connected together in a network where each constituent computer can communicate with others in the network.

In some cases, the computers in a network are very intimately connected, and the network appears to a user as a single but very large computer. We use the word system to mean either a computer, or a network of computers, that appear to the user as a single entity. A campus-wide UNIX network would be an example of such a system; a more loosely-connected network such as the Internet would not be. When using a terminal on a network, users are still communicating with a specific machine. Each window allows a dialogue with a single UNIX machine, and it is that target UNIX machine with which we shall be concerned in this book.