COMPUTER NETWORKS

INTRODUCTION

· A computer network consists of two or more computers that are linked in order to share resources, exchange data files or to allow electronic communication. The computers on a network may be linked through cables, telephone lines, radio waves, satellites or infrared light beans.

· There are two aspects of computer networks - hardware and software. Hardware includes physical connection between two machines by using adaptors, cables, routers, bridges, etc. software includes a set of protocols. Protocols define a formal language among various components. It makes hardware usable by applications.

Applications of Computer Networks

• Major application areas of computer networks are:

1) Business Applications

2) Home Applications

3) Mobile Computers

1. Business Application

• Now a days computers are being used in all business processes. For example, use of computers to monitor production, inventories, to make payments. Resource sharing is the important purpose of using computer networks. Resources like programs, equipments and data are required to share amongst various users.

a) Database resource :

• The database is required to access for decision making by various departments. The database is maintained by dedicated server and users (clients) can access the data. One server can provide service to many clients.
  
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• Client requests foe a service and server acknowledge the request. The server performs the requested work and sends back the result .the process of and reply for a client.

b) Communication medium:

Computer network is a powerful medium for communication. E-mail is very popularly used amongst company employees. Video-conference is other form of computer assisted communications.

c) Electronic commerce:

· Many companies doing business electronically with suppliers and customers. Customers can place order electronically; this assures fast delivery and efficient services

2. Home Applications

· Now a days, use of computers in home is wide spread. Popular uses of computers in home are as under.

1) Internet access 2) personal Communication

3) Entertainment 4) Electronic Commerce.

· Various magazines, scientific journals, e-books are available online. Many professional organizations also provide their journals, conference proceedings online.

· E-mail, instant messaging, chatting, Internet telephony, Video phone provides personal communication by using internet and WWW.

2. Mobile Computers

Many Professionals uses desktop computers at office and want to be connected to the office network while travelling and at home also. This is possible by wireless networks, hence use of Laptop, notebook computers and personal Digital Assistants (PDAs) is increased. With the help of wireless networks one can access Internet, read and e-mail. Wireless networks are used in :

1) Taxis, delivery vehicles and other mobile vehicles for keeping contacts with their office.

2) Geographical information system (GIS)

3) Military applications

4) Airports

5) Banking

6) Weather reporting

COMPUTER NETWORK