Introduction

A Computer network consists of two computers connected to each other by a cable that allows them to share data. This connecting together of computers and other devices is called a network, and the concept of connected computers sharing resources is called networking
It arose as an answer to the need to share data without the need of  print out documents or copy document files to a disk for others to edit or use them.  in a timely fashion. Personal computers are powerful tools that can process and manipulate large amounts of data quickly, but they do not allow users to share that data efficiently.

Simple computer network 

Networks increase efficiency and reduce costs by :

• Sharing information (or data)
• Sharing hardware and software
• Centralizing administration and support