A network is a group of computers that are able to communicate with each other.
A network can consist of Laptops, Desktop PCs, Tablets, Smartphones, Printers, Servers etc.
Networks are used for a number of reasons:
Sharing files between devices
Ability to back up files
Central maintenance and support
A network can be both wired and wireless or a combination of both.
You may be part of a network now as you use this resource:
At school you will be connected to servers that store your data and provide an internet connection
At home you may be connected to a router which could allow you to share files with other connected computers
A network can be one of several different sizes, all you need to learn is the most common two:
A Local Area Network (LAN) - is a network that are within a single building or site
The owners of the business using the LAN will own all of the components and devices, and therefore everything beyond the telephone line is of responsibility to the owner
In a home, the bill payer may not own the router if it’s part of a contract agreement (E.g. Sky), but the rest of the components and devices within the network will be owned
Example of a LAN
A Wide Area Network (WAN) - is a network that is spread over a wider area and multiple sites
The owners of the business using the WAN will be using components between sites that are not owned, e.g. telephone wires between buildings that are owned by BT
This means that the communication links between sites are owned and looked after by another company (such as BT) and therefore there is most likely a cost for the service
A common misconception is that if you were to run your own cable from one site to another, this would be classed as a WAN due to the distance. This is incorrect as you would own the cable between the two sites, unlike if you were to use a third party cable in order to connect; therefore this would still be a LAN.
Example of a WAN
Before a computer can be connected to a network it needs to have a piece of hardware known as a network interface card (NIC) or wireless network interface card (WNIC).
A network interface card is simply a small circuit with a socket for an Ethernet cable
A wireless network interface card is simply a small circuit with an antenna to send/receive data
On older generation computers this antenna will stick out the back, on modern computers it won’t
The computer will then need to connect to a hub or switch
A hub is a device that is able to connect multiple computers to a network and send data round the network
A switch is the same as a hub, except is able to process data and direct it to the intended device which improves overall speed
The hub/switch is connected to a router which connects to a modem which uses a phone line to provide access to the internet
Most modern routers contain a modem, especially those used in the home (E.g. from Sky)
Components of a computer network
Client–Server Network - in which server computers provide services for client workstations.
Hub - Device that channels a number of input signals into one output line.
LAN - Local area network
NIC - Network interface card/controller
Packet - A unit of data sent on a packet switching network.
Peer-to-Peer Network - in which all the computers are of equal status.
Topology - The layout of a network. WAN Wide area network