February 27th, 2018 - Computer Networking

posted Feb 28, 2018, 6:00 AM by Mr Becker   [ updated Feb 28, 2018, 6:47 AM ]

A computer network is a number of computers linked together to allow them to share resources. Networked computers can share hardware, software and data.

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 and email.

There are two main types of networks:

  1. Local Area Network (LAN)

  2. Wide Area Network (WAN)

A LAN covers a small area such as one site or building (ex: a school or a college).

Shows multiple workstations connected in a circle,  including a server.

A WAN covers a large geographical area. Most WANs are made from several LANs connected together.

Shows a WAN, made from several smaller networks, which could be local area networks (LAN). Each of the smaller networks has it's own server and multiple workstations connected.

  • The Internet is 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 of networks include:

  • Sharing devices such as printers saves money.

  • Site (software) licences are likely to be cheaper than buying several standalone licenses.

  • Files can easily be shared between users.

  • Network users can communicate by email and instant messenger.

  • Security is good - users cannot see other users' files unlike on stand-alone machines.

  • Data is easy to backup as all the data is stored on the file server.

Disadvantages of networks include:

  • Purchasing the network cabling and file servers can be expensive.

  • Managing a large network is complicated, requires training and a network manager usually needs to be employed.

  • If the file server breaks down the files on the file server become inaccessible. Email might still work if it is on a separate server. The computers can still be used, but are isolated.

  • Viruses can spread to other computers throughout a computer network.

  • There is a danger of hacking, particularly with wide area networks. Security procedures are needed to prevent such abuse (ex: a firewall).