Definition of Computer Networks
On this occasion , ane carries a structured article that discussed the definition of Computer Networks . The computer network is a system that consists of computers that are designed to be able to share resources ( printers , CPU ) , communicate ( email , instant messaging ) , and access to information ( web browser ) . The purpose of the network is the computer in order to achieve its objectives , each part of the computer network may request and provide the service or services . The party requesting / receiving service called ( client ) and that provide / send the service is called a server . This design is called a client-server system , and is used in almost all computer network applications .
Two computers , each of which has a network card , then connected via a wired or wireless data transmission medium , and there is a network operating system software to form a simple computer network . If you want to create a computer network that is wider -reaching , it would require additional equipment such as Hubs , Bridges , Switches , Routers , Gateways as interconnection equipment .
The history begins with the birth of the computer network computer network concept in the 1940s in America was initiated by a computer development project at Bell Labs Model I and the research group led by Harvard University professor Howard Aiken . At first the project simply want to take advantage of a computer device that must be used together . To carry out the process without much wasting some free time made the streak ( Batch Processing) , so that multiple programs can be run in a computer with the rules of the queue .
Then in the year 1950 when it began developing the type of computer to the creation of a super computer , then the computer should serve some places available ( terminal ) , for it is found the concept of time-based distribution process known as TSS ( Time Sharing System ) . So for the first time form a network (network ) applied computer . In some terminal TSS system connected in series to a computer or other device connected to a network ( host ) computer . In the process of TSS is starting to look a fusion of computer technology and telecommunications technology that was originally evolved on their own . U.S. Department of Defense , the U.S. Defense Advanced Research Projects Agency ( DARPA ) decided to conduct research that aims to connect several computers to form an organic network in 1969 . This research program known as the ARPANET . In 1970 , already more than 10 computers which successfully connected to each other so that they can communicate with each other and form a network . And in 1970 it was also after the workload increased and the price of a large computer devices began to feel very expensive , then start to use the concept of process distribution ( Distributed Processing ) . In this process some of the host computer is doing a great job in parallel to serve multiple terminals which are connected in series in each host computer . In the distribution process has been absolutely necessary blend of deep between computer technology and telecommunications , because in addition to the process that must be distributed , the host computer must serve all the terminals in a single command from the computer center .
In 1972 , Roy Tomlinson managed to complete the program electronic mail ( e-mail ) is made one year ago to the ARPANET . The program is so easy to use , it immediately became popular . In the same year ie 1972 , the icon at ( @ ) is also introduced as an important symbol that shows the " at " or " on " . In 1973, the ARPANET computer network developed extends beyond the United States . Computer University College in London is the first computer that is outside the United States who are members of Arpanet network . In the same year ie 1973 , two computer experts that Vinton Cerf and Bob Kahn presented a bigger idea , which became the forerunner of thought International Network ( Internet ) . This idea was presented for the first time at the University of Sussex . The next historic day 's dated March 26, 1976 , when the Queen of England managed to send electronic mail from the Royal Signals and Radar Establishment , Malvern . A year later , more than 100 computers on ARPANET joined to form a network or network .
Tom Truscott , Jim Ellis and Steve Bellovin , creating the first newsgroups called USENET (User Network ) in 1979 . In 1981 , France Telecom creates something new with the launch of the first television phone , where people can call each other that is also associated with the video link .
As we get computers that make up the network , it takes a formal protocol that can be recognized and accepted by all the networks . To that end , in 1982 established a Transmission Control Protocol ( TCP ) or better known as Internet Protocol ( IP ) that we know today . Meanwhile , in Europe appears a similar network known as Europe Network ( Eunet ) which covers an area of the Netherlands , the UK , Denmark , and Sweden . [ 6 ] This Eunet Network provide electronic mail and USENET newsgroups .
To homogenize the address on an existing computer network , then in 1984 introduced a Domain Naming System or the domain name system , which we now know with DNS . Computer connected to the existing network already exceeds 1,000 computers more . In 1987 , the number of computers connected to the network jumped 10 -fold to 10,000 more .
Computer networks continue to grow in 1988 , Jarkko Oikarinen find a Finnish nationality at the same time introducing Internet Relay Chat , or better known by the IRC that allows two or more computer users can interact directly with the delivery of messages ( chat ) . As a result , a year later the number of interconnected computers jumped 10-fold . no less than 100 000 computers to form a network . Mid-1990s is the most historic year , when Tim Berners Lee to design a programe editors and explorers can menjelajai computers to each other to form a network . Programe is called Waring Wera Wanua or the World Wide Web .
Computers that are connected to form a network has exceeded a million computers in 1992 . And in the same year the term surfing ( surf ) . And in 1994 , the sites on the internet has grown into a 3,000 page address , and for the first time to shop via the internet or virtual - shopping or e - retail appear on the site . In the same year Yahoo was founded , which is also at the same year of birth Netscape Navigator 1.0 .
Classification of computer network is divided into :1.Berdasarkan geographicalThe computer network is divided into a local area network or Local Area Network ( LAN ) , metropolitan area networks or Metropolitan Area Network ( MAN ) , and wide area network or wide area network ( WAN ) . Local area network ] ] is a private network inside a building or place that size up some 1-10 kilometers. LANs are often used to connect personal computers and workstations ( workstations ) in a corporate office or factories to use shared resources ( eg printers ( printers ) and exchange information . Meanwhile, a metropolitan area network LAN network expansion to include the city which is quite extensive, consisting of dozens of buildings within 10-50 miles . transmission cable used is a fiber optic cable ( fiber optic ) . networks wide area network is an intercity , inter- provincial , inter- state , even between continents . could include the distance around the world , for example, a network that connects all banks in Indonesia , or a network that connects all Indonesian representative offices around the world . primary transmission medium is communication via satellite , but many are relying on fiber-optic connections between countries .
Based on the function , divided into client - server network ( client - server ) and End to end Network ( Peer - to-peer ) . Client - server network on one computer ddasaranya be prepared waiter ( server ) from the other computer as a client ( client ) . All service requests from the client computer resource should be passed to the computer waiter , waiter 's computer will adjust its service . If communication is very busy service requests could even put up more than one computer into a waiter , so there is a division of tasks , such as file - server , print - server , database server , and so on . Of course waiter computer configuration is usually more than the client computer configuration both in terms of memory capacity , hard drive capacity , and speed processor . While the network end to end is indicated by computers together so each computer can request the use of shared resources from other computers , so too must be ready to serve requests from other computers . [ 8 ] The network model is usually only applied to the number of computers not too much , maximum 25 , because the communication would be complicated and bogged down when the computer too much .2 . Based on the network topology , computer networks can be distinguished :
bus topology
star topology
ring topology
mesh topology
tree topology
linear topology
3 . Based on the distribution of resources / data
centralized network
This network consists of a client computer and the server where the client computer that serves as an intermediary to access sources of information / data from one computer server .
distributed network
Distributed Network erupakan blend some centralized network so that there are several interconnected computer servers with client systems form a specific network .
4 . Based on a data transmission medium
Wired Network ( Wired Network )
In this network , to connect one computer to another computer connecting a network cable is required . Function in the network cable to send information in the form of electrical signals between the network computer .
Wireless network ( Wi - Fi )
Nirkaberl network or WI - Fi network is the medium in the form of electromagnetic waves . In this network cables are not required to connect between computers because it uses electromagnetic waves that would send a signal information between networked
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