First 514 words of the document:
What is a network?
At home, the computer might be connected to its own
printer and scanner. This works well as you are the only
person who will be using them. Much of the time though,
they probably aren't being used and just lie idle. A
computer which isn't connected to a network is known as
In a school or an office, it would cost a lot of money for
every computer to have its own printer and for the
majority of the time, like your printer at home, it
wouldn't be used.
By joining computers together to form a network, they are able to share one printer.
This means that more money can be spent buying a better quality printer and that the
printer is being used much more of the time.
As well as sharing hardware, a network allows computers or users to share software
and data. A computer connected to a network is known as a 'work-station'.
Local Area Network
When the computers are fairly close to one another say, in a single office or two
buildings that are separated by a road, they can be joined together either by cables or
These computers then form a Local Area Network (LAN).
Once the computers are connected together into a LAN, many people (users) can share
and use the same resources at the same time. They can share files, software, hard
disks and peripherals such as a printer or CD-ROM. Users can also use the LAN to
communicate with each other by e-mail. Data can be transmitted very quickly between
A file server is often used to store each person's data files. This means that people
can log onto any machine on the network and access their files. They are not restricted
to just one machine. Another advantage of having all of the files stored in one place is
that a back up copy of every users files can be made easily.
To log onto a LAN, you usually need a user name and password. The user name identifies
you to the file server so that it can 'serve' you the correct files. The password ensures
that the user name really does belong to you.
Wide Area Network
Many modern companies have offices, shops or factories in various locations around the
country, and for large
corporations, across the world.
Even though staff work in
different places, they often need
to be able to access the same
information no matter where they
It would not be possible to
connect computers in different
buildings together using the LAN
cables. Imagine how many roads
would need to be dug up to lay
cables between a building in
London and one in Birmingham.
Other pages in this set
Here's a taster:
Computers on LANs in one building can be connected to computers on LANs in another
building usually through the telephone system, often using a modem. They can also be
connected via fibre optic cables, microwave links or satellite.
By linking LANs together, the network is no longer local to one building, it is now
spread over a wide area.…read more
Here's a taster:
On the whole, the advantages of networks outweigh the disadvantages. This is why they
are so commonly found in schools, offices and factories. Even home users are starting
to use networks to connect PCs around the house.
This is one method of connecting computers together and is the simplest one to connect
A single cable joins all of the workstations, printer, file server and other components
together. At each end of the bus is a 'terminator'.…read more
Here's a taster:
Low security - every workstation can see all of the data in the network
Limited cable length and a maximum number of workstations
In a ring network layout, all of the computers are connected to one another in a circle.
The data passes from one computer to the next one and then all the way around the
ring layout until it reaches the destination computer.…read more