A computer network is a system of computers designed to share resources (printer, CPU), communicate (email, instant messaging), and can access information (web browsers). The purpose of the computer network is To be able to achieve its purpose, every part of the computer network can request and provide services (service). The requesting / receiving party of the service is called the client and the sender / sending service is called server (server). This design is called the client-server system pengeluaran togel, and is used in almost all computer network applications.
Two computers each have a network card, then connected via wire or wireless as data transmission medium, and there is network operating system software will form a simple computer network : If you want to create a wider computer network again the range, then required additional equipment such as Hub, Bridge, Switch, Router, Gateway as interconnection equipment. 
COMPUTER NETWORK HISTORY:
The history of computer networks stems from the birth of the concept of computer networks in the 1940s in America which was initiated by a computer development project MODEL I in Bell lab and Harvard University research group led by professor Howard Aiken. At first the project was just to use a computer device that must be shared. To work on multiple processes without wasting a lot of free time is a batch process, so some programs can run on a computer with queue rules.
Then in the 1950s when the type of computer began to develop until the creation of a super computer, then a computer must serve several places available (terminal), so for the first time the form of computer network (network) is applied. In TSS systems some terminals are connected in series to a computer or other device connected in a host computer. In the poker88 process of TSS began to look fusion of computer technology and telecommunications technology that originally developed independently. US Department of Defense, U.S. The Defense Advanced Research Projects Agency (DARPA) decided to conduct research aimed at connecting a number of computers to form an organic network in 1969. The research program is known as ARPANET. In 1970, more than 10 computers were successfully connected to each other so that they could communicate with each other and form a network. And in 1970 it was also after the burden of work increased and the price of large computer devices began to feel very expensive, then begin to use the concept of distribution process (Distributed Processing). In this process some host computers work on a large work in parallel to serve multiple terminals that are connected in series to each host computer. In the distribution process is absolutely necessary in-depth integration between computer technology and telecommunications, because in addition to the process that must be distributed, all host computers are obliged to serve the terminals in a command from the central computer.
This is the Model Time Sharing System (TSS)
In 1972, Roy Tomlinson succeeded in perfecting the e-mail program he created a year ago for the ARPANET.  The program is so easy to use, so it instantly becomes popular. In the same year of 1972, the icon at (@) was also introduced as an important symbol indicating “at” or “on”. In 1973, the ARPANET computer network began to expand beyond the United States. The University College computer in London was the first computer outside the United States to become a member of the Arpanet network. In the same year of 1973, two computer experts Vinton Cerf and Bob Kahn presented a larger idea, which became the forerunner of the International Network (Internet) thinking. This idea was presented for the first time at the University of Sussex. The next historic day was 26 March 1976, when the Queen of England managed to send electronic mail from Royal Signals and Radar Establishment in Malvern. A year later, more than 100 computers joining the ARPANET formed a network or network. Source: wikipedia.com