A network consists of a number of computers and peripherals connected together.

Advantages of networks...

• hardware can be shared (eg.a number of computers can use the same printer)
• software can be shared (eg a number of workstations can all load up a program from a file server)
• data can be shared (eg a number of computers can access the same database stored on a file server)
• computers may communicate between each other (messages / email)

Disadvantages of networks over standalone computers:

• viruses can be spread to all computers on a network
• hackers may access computers on a network.
• network failure means nobody can use the computers
• networks may be slower than using standalone computers
• complex cabling may be expensive to install

A Local Area Network (LAN) is connected by cable, usually on the same site.

A Wide Area Network (WAN) is connected by telephone or satellite links, possibly in different towns, countries...

It is important that networks adopt standards - common methods of sending data and consistent data formats. If they did not operate in the same way the workstations would not be able to communicate with each other.