A computer network is a number of computers linked together to allow them to share resources. Networked computers can sharehardwarehardware: The physical components of a computer.,softwaresoftware: A general term used to describe an application or a program.anddata [data:information without context, eg a list of students with numbers beside their names is data, when it's made clear that those numbers represent their placing in a 100 metre race, the data becomes information ].

Most computer networks have at least one server. A server is a powerful computer that provides one or more services to a network and its users. For example, file storage andemailemail: electronic mail - a message written or typed on a computer and sent electronically rather than by post.

LANs and WANs

There are two main types of network:

1. Local Area Network (LAN)
2. Wide Area Network (WAN)

LAN

A LAN covers a small area such as one site or building, eg a school or a college.

LAN - Local Area Network

WAN

AWANcovers a large geographical area. Most WANs are made from several LANs connected together.

WAN - Wide Area Network

• TheInternetInternet: a global network connecting millions of computersis a WAN.
• A network of bank cash dispensers is a WAN.
• A school network is usually a LAN.
• LANs are often connected to WANs, for example a school network could be connected to the Internet.
• WANs can be connected together using the Internet, leased lines or satellite links.

Advantages and disadvantages of networks

Advantages

• Sharing devices such as printers saves money.
• Site (softwaresoftware: A general term used to describe an application or a program.) licences are likely to be cheaper than buying several standalone licences.
• Files can easily be shared between users.
• Networknetwork: a group of interconnected computersusers can communicate byemailemail: electronic mail - a message written or typed on a computer and sent electronically rather than by postandinstant messengerinstant messenger: an application that allows users to send instant messages (text) to one another.
• Security is good - users cannot see other users' files unlike on stand-alone machines.
• Data [data: information without context, eg a list of students with numbers beside their names is data, when it's made clear that those numbers represent their placing in a 100 metre race, the data becomes information ]is easy tobackup [backup: to copy data onto a separate storage device in case the original device should fail, be damaged or the data stored on it get corrupted ]as all the data is stored on thefile serverfile server: a networked computer that provides large amounts of shared storage, it can be accessed by workstations on the same network.

Disadvantages

• Purchasing the network cabling and file servers can be expensive.
• Managing a large network is complicated…