Cocept of Network

The computer network use to provide the very efficient & good communication medium between the various people & the users.It also provides the many advantages as given below.Followings are the categories divided depending on geographical proximity:-

• LAN(Local Area Network)
• WAN(Wide Area Network)
• MAN(Metropolitan Area Network)
  

Network component

Now we are going to describe about how the local area network(LAN) work.The LAN can be work in two ways ther are (i) With the file server (ii) Without the file server

1. The file server:-This is the microcomputer which serves as the heart of network.This use to run the network operating systems software.Network operating systems use to enable file server for regulating the communication with other PC attaching to it & manage any shared resources that may be connected.File server must acquired one LAN interface board & also work intermediator between the sender & receiver.
2. Work station/Terminals/Nodes:-These are the PC which are operated by the network users.Each of the work station use to process their own files by using their own operation systems or the windows.You also can see them in workgroup systems.So kind of the software to be loadedinto every workstations for communicating with files server & other work station on network.SHELL also use to redirect the request from workstation to network to file server.
3. UPS(Uninterrupted Power Supply):-This is attached to file server & will provide file server the continuous flow of the electricity, if the sudden power is cut off.This is the device which use to provide the power to file server or computer from the 15 minutes to 2 hours from it's internal backup storage.
4. Bridges:-This is the combination of the hardware & software which is connected to the network & that uses the same communication system.The bridge also can connect bridging take place outside file server.Therefore the bridge as the kinds of device that can be used to link the work stations with network.
5. Gate ways:-This use to connect the dissimilar system.This also can connect the network main frame & mini computer.As same as the bridge, this gate can be either the local or the remote.In other word, gate way can be defined as the device to join two or more the set of computer systems.This also passes message & help them to work with each other.
   

Computer network advantages

Followings are the advantages of the computer network:-

• Without regarding their physical locations, it provide all informations and datas to computer users which are connected to the network of computer.
• Sharing first computing abilities of one of computer, connected to network.
• Those computer which are connected to the network used for sharing files, hard disks, printers etc.
• The updated datas can instantly available dto everyone even updated by one person on network.
• Also help in the sharing of softwares between the member work station which saves money from bying multiple copies programmes system.
  

Introductions of network and the computer communications

Generally the communication means the exchanging or sharing of message & ideas between the two or more people.So, there is two ways to send the messages to the people or for the friends.They are simplex and Duplex.

• The simplex is one way communication systems for e.g. sending the letters by the mail, email, fax, telex books or newspapers, radio etc.
• The duplex is the two way communication systems, for e.g. internet, videos conferencing, telephone, tele medicine, money transfer, tele teaching, e-commerce etc.

The computers that are made today is use for sending and receiving the informations as the telephone systems.So because of the computer it has been easy & possible to make the comunications between two person or organization.So, for this purpose, the computers in different distance are to be connected together by the some means of forming which is called a network.The computer network is group of computer which are link together for the purpose of communicating & sharing resources.

Suppose think that there are twenty schools in your locality or districts in different cities and are distance apart & all of the schools have theirs own computer.Suppose if any special events is occured in any of one school & that school want to invite the principal other school.Here a very fast communications is required.For the fast exchange of message between the schools the perfect communications is essential.So what can be done is the computers of different schools must be connected so that each of it can be worked on it's own & if need arises.Therefore the communication link.This link may be done by the copper wire, micro-wav channel or even by the satellite or any other medium.

Computer network is defined as the collections of indepedent computer connected through communication medium.For making network each and every computer must be able to work independently.There was remarkable and the great changes in the world of communication after 1994A.D.By using the computer network and the telecommunication, people can use computer for reaching, processing the records in other PC, retriveing and reinting the results on their own counters.So by the help of computer network and the telecommunications, followings services are being provided by the people to their customers.

1. Communication of Data

• Telegram
• Telex
• E-mail
• E-commerce, E-trade, E-mail, E-business

2. Communication of Voice(Transfer voice)

• Telephonic
• Radio

3. Communication of Videos(Transfering motion pictures)

• Video phone
• Television
• Video text
• Video conference

The above technology are being used by th people in today's world more than 20millions for their own purpose.They are busy in theri jobs throughout the days & night.For converting the characters, numbers, videos, texts in the electrical pulse & vice versa, all of them requires a device called MODEM which is the combinations of pair like Demodular & Modular.So to use the above technology mentioned, users need a computer, telephone set and modem.