What Is Computer Network | Advantages,Components,Types,Benefits

What Is Computer Network | Advantages, Components, Types, Benefits

What Is Computer Network?

Networks are not new to us. We are familiar with postal networks, rail-way networks, airline networks, etc. Networks allow us to do various kinds of functions efficiently without much of effort. Evolution of computer has affected many areas of our life and computer network is one of the most popular and useful network in today life, even one cannot think life without computer.

Computer network is a kind of Data transfer arrangement which connects different types of computers and their attachments in such a way that they can communicate with each other by transferring any kind of data (picture, voice, document, clip etc.) in the form of electrical signals. For this it is not necessary that computers are near to each other or very far to each other. SNA (System Network Architecture) was the first computer network developed by IBM to establish the link between its computers and it was limited to company only. This type of personal network is known as Intranet.

Benefits of Computer Networking

There are so many benefits of computer networking. Few of them are as follows:

• Sharing of Resources: Computer network allows every computer on a network to share other computers and their resources like printer, scanner, CD-drive, hard disk etc. This advantage allows all the computers of a network to use single printer, scanner etc. which reduces expenses as well as maintenance. One user can work on more than one computer at a time.

• Sharing of Data and Information: It is necessary for an organization to have latest information for its development. Suppose an organization has hundreds of branches all over the world. To work in a proper manner it need to communicate with all the branches and share data and information time to time. Computer network allows such type of organization to do so in no time. Similarly, one can use shared information through computer network easily. 

• Reliability of Information: Working of banks, railways, stock market, etc. is solely depends upon information and data. For them it is necessary to keep their important information secured and easily available The information through computer network is more secured as compared to manual. It reduces the probability of stealing and missing.

• Economy: Use of computer network saves time as well as money. One can share information resources which reduces the cost of working Personal computers have better price/performance ratio than mainframe computers. So it is better to have PCs one per user, with data stored on one shared bile server machine. There are so many economic facilities available on internet which save our money like e-mail, chatting, conferencing, etc.

• Communication Medium: Using a computer network, it is possible for a person to communicate with other by using various facilities. Computer network allows written, verbal as well as visual communication among individuals.

Advantage Of Computer Network

A networked computer can do so many things which a stand alone computer cannot do, like: It can share copies of single file among many users at the same time.
It makes organizations almost paperless because information through different places is transferred through network and stored on computers.

It can share applications of entire network, which reduces the cost of purchasing multiple softwares.
It can share computer resources like scanner, printer, fax machines, etc. which reduces cost of purchasing separate resources. It can transfer files and other information easily without using devices like floppy, CD, etc.Large amount of information can be used without much worrying about storage capacity.

Components of Computer network

A network is a combination of different components. The most essential components of a computer network are:

Servers : Servers are the faster computers to run different softwares/programs, to store and process information and to provide a human interface of the users to be able to use the networked computers. 

They are of two types :

1. Dedicated Server : Only make the information available for other computers of the network.
2. Non-dedicated Server: It works as both service provider as well as client.

Nodes : Nodes are the computers on the network, which are provided to the users to carry out their tasks using the network. A node, which is more powerful and can handle local information processing or graphics processing is called a workstation. They are responsible for receiving and transmitting signals. Every node in a network has a unique IP address.

IP address : Network administrator provides an Internet Protocol Address (IP address) to every node in the network, which helps in recognising different nodes. Same IP address cannot be given to other computers of the same network. In this, there are four numbers separated by (.) dots e.g., 255.10. 15. 10.

Cables : This is a medium over which the information travels from one computer to another. From the computer on to the medium (cable) and to take up the information from the medium and make it available to the computer in the form it can read. LAN cables can be categorised in three groups:

• Twisted Pair
• Coaxial Cable
• Fibre Optics

Network Operating System (NOS) : It is used to control the movement of information on the network. Networks, which are more complex, require components like HUBS, Switches and Routers to carry out different network functions.

Network Interface Card: This is used to connect the cables to the computers. These cards help the computer to transfer the data at a faster rate and in the form of packets. These cards are plugged into the computer motherboard. These cards are generally called as Ethernet cards.

Modem : Modem is an electronic device which converts digital signals into audible form that can be transmitted over ordinary analog lines. This is called modulation. On the receiving end a modem demodulates the signals into electrical signals that are then fed to the computer. MODEM is an abbreviation for MODULATION and DEMODULATION.

Types of network on the basis of geographical distances

(1) Local Area Network (LAN) 

LAN is a system of hardware, software and communication channels that connect devices on the same premises. This network permits data movements between the central computer, intelligent work-stations, dump terminals and other I/O devices. Ethernet, developed by Xerox Corporation, is a famous example of LAN. This net- work uses coaxial cables for data transmission. Omninet developed by Corvus System is another example of LAN. This particular network has the ability to interconnect different microcomputer systems such as Radio stack, Apple.

Characteristics of the LAN :

• Nodes are located in a relatively limited geographic area (less than 15 miles)
• Owned by single organization.
• Usually decentralized control.
• High data rate.
• Low error rate.
• Inexpensive transmission medium (e.g., coaxial).
• Maintenance is easy.

(2) MAN (Metropolitan Area Network)

MAN is a network which covers larger area than LAN. Generally it is used to connect big cities to each other for the purpose of communication. Cable television network are example of MANS, distributing television signals.

Characteristics of MAN :

• Nodes are located in wider areas (generally connects the cities).
• Owned by big organization (Government, semi government or big private organisations)
• Data rate is slow as compared to LAN.
• Error rate is high as compared to LAN.
• Expensive.
• Maintenance is not easy.

(3) WAN (Wide Area Network) 

This network covers a very area with terminals connected to 1 or more hosts. WAN is an example of global network. Several LANS are connected to form a MAN and several MANS are connected to form a WAN. Such networks use line concentrators to reduce communication costs and usually provide dial in access over telephone lines. ARPANET or the Advance Research Project Agency of the U.S. Department of Defence is an example of WAN. This network connects about 40 universities and research institutes. INDONET developed by Computer Maintenance Corporation (CMC), India is also a WAN.

Characteristics of WAN :

• Nodes are found over a much wider area.
• Usually used by several different organizations.
• Often access regulated public or private communication systems.
• Frequently used for large database access by users over telephone lines.
• Example- INFONET (Computer Science Corporation)