5.1.4 Computer Networks
|Candidates are expected to:
- be able
to identify the advantages and disadvantages of using common network
environments such as the internet.
What is a computer network?
A Computer Network is a system of connected computers, peripherals and
communication devices that can exchange information and share
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
The advantages of networking:
- Computers can communicate with each other
- Computers can share data and
- Storage facilities
can be shared.
- Hardware peripherals such as printers can be shared.
- There is control over which programs,
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
- 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
a network manager may need to be
employed to manage the system.
Common Network Environments:
- 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.
- 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.
- The Internet is the largest WAN. It is
a world-wide network
of linked computers sharing a vast amount of information.
- 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.
- 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
- 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.