Page 15 - DCAP406_DCAP_207_Computer Networks

Computer Networks/Networks

Notes 1.5.5 Internetworks

A collection of interconnected networks is called an internetwork or just Internet.
The Internet refers to a specific worldwide Internet that is widely used to connect universities,
government offices, companies and private individuals.

1.6 Uses of Computer Networks

There are many uses of computer network. Depending upon the users’ network has the following
uses.

1.6.1 Network for Companies

Resource Sharing: A network is needed because of the desire to make all programs, data, and
equipment available to anyone on the network without regard to the physical location of the
resource and the user. Load sharing is another aspect of resource sharing.
High Reliability: A network may have alternative sources of supply (e.g., replicated files, multiple
CPUs, etc.). In case of one resource failure, the others could be used and the system continues to
operate at reduced performance. This is a very important property for military, banking, air
traffic control and many other applications.
Saving Money: A network may consist of many powerful small computers, one per user, with
data kept on one or more shared file server machines, which offers a much better price/
performance ratio than mainframes.
Scalability: The ability to increase system performance gradually by adding more processors
(incremental upgrade).

Powerful Communication Medium: Networks make cooperation among far-flung groups of
people easy where it previously had been impossible.
In the long run, the use of networks to enhance human-to-human communication may prove
more important than technical goals such as improved reliability.
CSCW (Computer-Supported Cooperative Work) is a rapidly expanding multidisciplinary area
based on communication networks.

1.6.2 Networks for People

Starting in the 1990s, computer networks began to start delivering services to private individuals
at home.

Access to Remote Information

(a) Home reservations for airplanes, trains, hotels, restaurants, theaters and so on, anywhere
in the world with instant confirmation.
(b) Home banking and shopping.
(c) On-line and personalized electronic newspapers, journals and libraries.
(d) Access to WWW (World Wide Web) which contains information about many topics - too
many to mention!
All these applications involve interactions between a person and a remote database.

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