We know, in information technology era, sharing of resources and easy communication are acting as a backbone of any network. Popular example is our Internet. With the help of internet we are able to exchange information and share resources. Hence in this chapter we study different advantages of the network and different forms of the network and their features.
The learning objectives of this chapter are to know
What is a computer network ?
How network is advantageous ?
What are different forms of networks ?
What is a e-mail ?
Networking of computers and its advantages.
Computer network is defined as an interconnection of autonomous computer. Here autonomous means, there is no master and slave relationship. All computers are equal. Computer network enables to share the resources. Computer networking also refers to connecting computers to share data, application software and hardware devices. Networks allow sharing of information among various computers and permit users to share files. For example a students accesses compilers sitting at one place, where compiler may be stored on the other machine. The students takes printout with the help of one printer connected to the network. The printer can be shared among many students.
Network offers the opportunity to communicate more efficiently with others through electronic mail. Networks allow companies to share software and peripherals such as printers, plotters, scanners and so on. With networking all the computers in an office can be connected to a single printer and scanner. It also helps in using storage devices efficiently.
Computer network acts as a very powerful communication medium. It means people exchange their information. When compared to mainframe computers, network of computers saves money.
Types of networks
Depending the nature of the distances, protocols ( the set of rules used for communication) the network can be classified into LAN (Local Area Network ), MAN (Metropolitan Area Network ) and WAN ( Wide Area Network).
Local Area Network (LAN)
A LAN (local area network) is a group of computers and network devices connected together, usually within the same building. By definition, the connections must be high-speed and relatively inexpensive (e.g., token ring or Ethernet). They function to link computers together and provide shared access to printers, file servers, and other services.
Any individual computer connected to a network is called workstation. A workstation may not need a floppy disk or hard disk. A LAN or local area network connects computers and peripherals in a limited area. LAN requires cables to connect workstations. For example LAN is used in a hall or within a building. Figure 5.1 shows Local Area Network , where various departments are connected.
Metropolitan Area Network (MAN)
A MAN ( Metropolitan Area Network) is used to connect computers to cover the city or town. The range may be approximately 50 Kilometers. Normally cables and fiber optic cables are used to connect computers. The routing of the messages are fast. Normally central library in a city may be connected by a MAN, so users can access the information. Figure 5.2 shows a typical view of Metropolitan Area Network.
Wide Area Network (WAN)
A WAN (Wide Area Network) covers large distance like state, country or continents. The WAN uses the fiber optics, cables and even satellites also. Here communication circuits are connected with the help of hardware device called routers. Routers forward small pieces of information called packets from one to another. Internet is the popular one comes under WAN. Some of the examples makes use of internet are reservation of airplane tickets, railway tickets and even cinema tickets. Another facility called e-commerce, where business is carried out through internet. Here people can buy books, articles and so on through registering their wants through the internet. Figure 5.3 shows a typical view of Wide Area Network.
The internet is a massive wide area network ,connecting thousands of computer networks around the world. The internet is a world wide “network of networks”. It is a collection of thousands of smaller networks in different countries around the world. It links thousands of academic government, military and public computers, enabling millions of people to share information and other resources.
Internet pathways are used to exchange digitized computer data. The basic services that form the foundation of the internet are e-mail , telnet and FTP. With internet we can easily exchange electronic mail with friends and family anywhere in the world.
Telnet allows you to connect to a remote computer. We can access any of the public services or tools and library databases at the remote site. FTP(File Transfer Protocol) provides for transferring files from one computer to another across the internet.
Internet has many uses. For individuals, the most important uses of internet are e-mail and surfing the Web. One can read the topics of interest like sports, a hobby, a country or any place of interest.
The e-mail stands for electronic mail. One of the major features of computer networking is that messages can be sent electronically to various terminals on the network. The messages are sent very quickly and accurately. E-mail uses the concept of Storing and forwarding messages. It saves a lot of money for the users. Here user registers his/her account with one of the providers. The e-mail account normally contains username and the provider name. For example abc @ yahoo.com , represents abc is the name of the user , who is registered in yahoo provider.
• Computer network is defined as a interconnection of autonomous computers.
• Computer networking enables us to connect computers to share data, application software and hardware devices.
• Networks allow sharing of information among various computers and permit users to share files.
• A LAN or local area network connects computers and peripherals in a limited area.
• A MAN covers the city or town.
• A Wide Area Network covers a large area.
• The internet is a massive wide area network, connecting thousands of computer networks around the world.
• E-mail is a cost effective communication
1. Computer network defined as a interconnection of ---------- computers
2. Computer network allows user to ----- the resources
3. -------- network confined to hall or building.
4. ------- is one example of WAN.
5. ------ business is carried our through internet.
6. Small piece of information called ---- are forwarded by router in Internet.
3. Local area