Modem Uses
Digital lines are used for transmitting large volumes of data at a
fast
rate. Analogue lines are often used by single users with little data
transfer, perhaps for a small amount of e-mail used over a
conventional
telephone line.
Advantages and Disadvantages
* Digital lines are more expensive to install than normal telephone
lines and
the line rental is higher.
* Modems must be purchased for use with normal telephone lines.
* There is much faster transmission rate typically found on digital
lines
because they have a higher bandwidth than an ordinary telephone line.
Computer Networks
A network of computers is when several computers have communication
lines
linking them. There are many types of computer network . One type of
computer network is when we have many individual computers linked so
that a
message may be sent from one to another. Another type of computer
network is
when we have one main computer called a network server. This controls
access
to work areas which are usually stored on the network server.
Uses
[IMAGE]A computer network is often used to allow users to share data
and software.
A typical example of where you will see a network in operation is in a
bank
or a supermarket. Cashiers in banks will have a computer on their
desk,
which can access the main network server computer so they can see your
account. Supermarket assistants sometimes have a smaller computer
known as
an electric point of sale (EPOS) the EPOS is connected to the main
network
server computer which stored all the details about the stock. In both
these
situations the main server computer controls access to shared data.
Advantages
When computers are networked together both programs ,for (example a
word
processor) and data (for example stock data) can be shared.
It is also possible for all networks users to communicate with one