Networks

A network is where two or more computers are connected. This means that they can share files and information with each other. People may use networks instead of stand alone machines as they all share the same information. Also, if a piece of software needs to be downloaded to more than one computer then having a network would make this more efficient as it would only need to be downloaded to the network and then it would automatically be on every computer on the system.

Computers can be connected by a LAN or a WAN. LAN stands for 'Local Area Network' and WAN stands for 'Wide Area Network'. These are two different types of terminal networks which can be adapted to how you use your computer. For an example, in your home you may use a LAN. This is because your house is in one building (or small geographical area) meaning that information doesn't need to be sent over a wide area. However, if you were working for a company and you needed to share information with somebody in another city, country or continent then you would need to use a WAN as this would enable you to share your information over such a wide geographical area.

Also, in a LAN computers are usually connected through a bus or star circuit. A bus circuit consists of several computers, terminators and servers such as a pint server and a file server. A bus circuit is a good circuit to use in a LAN because if there is a break in the chain then only one computer will be down. This therefore proves that a Bus circuit is more efficient than a ring circuit because in a ring circuit all of the computers are in one large ring, meaning that if there is a break in the circuit then the entire system is down. However, if you are willing to splash your cash then you may want to invest in a star network which links each individual computer directly to the servers. It costs a lot of money to do this as they is much more equipment needed and it will take a lot of time to set up. Though, there will be less network traffic so the system will be quite effective.

Cables can be used to connect computers in a network. In the past people would use ordinary cables. These weren't very efficient because not a lot of information can be sent very far without the system suffering from a lot of traffic. There is therefore a lot of interference and the data is sent painfully slowly. Now, people may use fibre optic cables which converts information into pulses of light which reflect through and bounce off the glass inside the cable. This is very fast and there is no interference. There is very little or no network traffic caused.

Below are links to pages which explain these ideas further:

Bus network animation: http://www.teach-ict.com/gcse/hardware/networks/djp/mov_busnetwork.swf

Ring network animation: http://www.teach-ict.com/gcse/hardware/networks/djp/mov_ringnetwork.swf

Star network animation: http://www.teach-ict.com/gcse/hardware/networks/djp/mov_starnetwork.swf

Network toplogies presentation: http://www.teach-ict.com/contributors/clare_belshaw/networks/networks.html

Hardware and software in a LAN: http://www.teach-ict.com/gcse/hardware/networks/theory/network_components/network_components.html

Network communications: http://www.teach-ict.com/gcse/hardware/networks/theory/network_communications/network_communications.html