5.1.4 Computer Networks

What is a computer network?

A Computer Network is a system of connected computers, peripherals and communication devices that can exchange information and share resources.

The network includes the computer systems, the connections and the hardware needed to allow the communication.

Networks can be limited to a building/area (a Local Area Network or LAN) or worldwide such as the Internet (a Wide Area Network or WAN)

The advantages of networking:

• Computers can communicate with each other easily
• Computers can share data and files.
• Storage facilities can be shared.
• Hardware peripherals such as printers can be shared.
• There is control over which programs, data and hardware a user has access to.
• Data can easily be backed up centrally.

The disadvantages of networking:

• A virus can spread more easily. If a virus gets into one computer, it is likely to spread quickly across the network because they are linked.
• As data is shared there is a greater need for security. Users of the network have to have user ids and passwords.
• If the server fails, all the workstations are affected. Work stored on shared hard disk drives will not be accessible and it will not be possible to use network printers either.
• The cost of installing the equipment is greater. Cabling can be expensive to buy and to install.
• Damage to cables can isolate computers. Some sections of the network can become isolated and will not be able to communicate with the rest of the network.
• Because networks can be complicated to maintain, a network manager may need to be employed to manage the system.

Common Network Environments:

An intranet:

• An intranet provides information using web pages but the information can only be accessed from the local network or by logging on from a wider network such as the Internet.
• Advantages:
  • An Intranet is free to use because it does not involve phone links.
  • Information can be easily updated and shared inside a company or school.
  • The web pages can be viewed using a standard web page browser.
  • More of the information will be useful because it was created for particular users. 
• Disadvantages:

  • Information cannot be shared outside the local network without logging onto the Intranet

The Internet:

• The Internet is the largest WAN. It is a world-wide network of linked computers sharing a vast amount of information.
• Advantages:
  • Millions of people contribute information.
  • Data can be rapidly added and updated to reach a huge audience.
  • It can be used to sell goods to a world-wide market.
• Disadvantages:
  • There is a lot of useless information, much of which is out of data and it can be very difficult to find what you want.
  • Much of the information is biased, misleading or has not been checked for accuracy.
  • It is not regulated and offensive and illegal material exists.
  • Issues such as security become even more important as potential hackers could possibly be trying to break into a computer system from anywhere in the world.