Internet_ Baidu Encyclopedia

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the Internet is a collection of global information resources. There is a rough view that the Internet is a logical network formed by many small networks (subnets), in which several computers (hosts) are connected. Internet aims to exchange information resources with each other, based on some common protocols and through many routers and public Internet. It is a collection of information resources and resource sharing.

computer network is only the carrier of information, while the superiority and practicability of Internet lie in itself. Internet top level domain names are divided into institutional domain names and geographical domain names. There are mainly 14 kinds of institutional domain names.

it connects all the computers. People can find different information from the Internet. There are millions of useful information for people. You can use search engines to find the information you need. The Internet is an international computer network. It connects computer networks all over the world.People can get different kinds of information from it.There are millions of websites on the Internet.There is a lot of usefulmation on the websites.You can use search engines to find the information you need.Search engines help us find information quickly and easily.Type in a keyword or keywords and the search engine will give you a list of suitable websites to look At.

Internet is the Chinese translation of “Internet”. It originated from the Pentagon of the United States. Its predecessor was ARPANET, which was developed by the Advanced Research Projects Agency (ARPA) of the US Department of defense.

in the late 1950s, it was in the cold war period. At that time, the U.S. military built a military network called ARPANET by the Advanced Research Projects Agency (ARPA) of the U.S. Department of defense at that time for its own computer network to be attacked

, even if part of the network was destroyed, the rest could still maintain communication. ARPANET was officially launched in 1969, when only four computers were connected for scientists to conduct computer networking experiments. This is the predecessor of the Internet.

by the 1970s, ARPANET had dozens of computer networks, but each network could only communicate with computers inside the network, and different computer networks could not communicate with each other. Therefore, ARPA has set up a new research project to support the academic and industrial research. The main content of the research is to use a new method to interconnect different computer LANs to form the “Internet”. Researchers call it “Internet”, or “Internet” for short, and the term has been used until now.

computer software plays an important role in the research and implementation of interconnection. In 1974, there were protocols to connect packet networks, including TCP / IP, the famous Internet Protocol IP and TCP. The two protocols cooperate with each other. IP is the basic communication protocol, and TCP is the protocol to help IP achieve reliable transmission.

one of the most important features of TCP / IP is openness, that is, both TCP / IP specifications and Internet technologies are open. The purpose is to make computers produced by any manufacturer communicate with each other and make the Internet an open system. This is the important reason why the Internet has developed rapidly.

ARPA accepted TCP / IP in 1982, selected Internet as the main computer communication system, and converted other military computer networks to TCP / IP. In 1983, ARPANET was divided into two parts: one was military, called milnet; the other was still called ARPANET for civilian use.

in 1986, the National Science Foundation of the United States (NSF) interconnected five supercomputer centers serving scientific research and education in the United States, and supported regional networks to form NSFNET. In 1988, NSFNET replaced ARPANET as the backbone of the Internet. NSFNET backbone network makes use of TCP / IP technology which has been proved to be very successful in ARPANET, and allows universities, governments or private research institutions to join the network. In 1989, ARPANET was disbanded, and the Internet changed from military to civilian.

the development of Internet has aroused great interest of merchants. In 1992, IBM, MCI and merit jointly set up an advanced network service company (ANS) and established a new network called ansnet, which became another backbone network of the Internet. Different from NSFNET, NSFNET is funded by the state, while ansnet is owned by ans company, which makes the Internet begin to commercialize.

on April 30, 1995, NSFNET officially ceased operation. At this time, the backbone network of the Internet has covered 91 countries in the world, with more than 4 million hosts. In recent years, the Internet has moved forward at an amazing speed, and has quickly reached its scale. The exact timing of the Internet’s generation of information is different. Some people believe that the success of ARPANET’s experimental networking in 1972 marked the birth of the Internet. Others regard the conversion of all ARPANET connected networks to TCP / IP in 1993 as the time when the Internet came into being. However, in any case, the emergence of the Internet is not an isolated and accidental phenomenon, it is an inevitable result of the continuous pursuit of the ideal of information resources sharing, so the origin of the Internet can be traced back to earlier times.

in recent decades, human beings have made important progress in this field, laying the foundation for the emergence of the Internet. For example, in 1957, the first man-made satellite was launched, which raised the ability of human beings to transmit information to an unprecedented level, and opened a new era of satellite communication. In the 1970s, the emergence of microcomputers indicated that the popularization of information technology was possible; the use of laser and optical fiber technology expanded the processing and transmission of information from “point” to “surface”. In recent ten years, the combination of computer and communication technology, especially the development of network technology, has promoted a wider range of network interconnection and information resource sharing.

according to the literature, J. C. R. likley of Massachusetts Institute of technology was the first person to put forward the idea of information exchange through the Internet. In August 1962, he put forward the concept of “giant network” in his article “on-line man-machine communication”. He assumed that everyone could quickly obtain data and information at any place through a globally interconnected facility. In terms of its spiritual essence, this network concept is very similar to the Internet. He was the first leader of DARPA, which later became ARPA. His successors, B. Taylor and L. g. Roberts, were convinced of the importance of this network concept and made important contributions to its further development and improvement. Packet switching theory the development of Internet is based on the early research of packet switching and related technologies.

L. Kleinrock of MIT published his first paper on packet exchange theory in 1961 and his first book on it in 1964. Packet switching mainly refers to dividing long information into several packets in communication network. Each packet is like an envelope, which contains the message to be delivered and the address to be delivered to the destination. In addition, there is a number representing the location of the packet in the whole information flow. Any packet that is lost or blocked can be resend. When all packets arrive at their destination, the receiver recombines the digital blocks into complete information. This network, known as packet switching, enables multiple computers to use the same communication line, or allows a data stream to pass over congested lines and quickly transfer through other paths. The theory of using packets instead of lines for communication is an important step in the direction of network technology. Another important development is the ability of computers to transmit information to each other. By coincidence, we almost studied packet exchange theory with MIT (1961-1967). At the same time, the National Physics Laboratory of England (1964-1967) also carried out similar research, and each other did not know each other’s research. The military computer network ARPANET Internet is based on the military computer network ARPANET.

ARPANET is the earliest and most typical example of computer networks. It is an experimental network jointly developed by researchers from the US Department of defense and some universities in the late 1960s. Considering the military defense strategy at that time, the U.S. Department of defense thought that a centralized management network was very fragile and could not withstand the destruction of nuclear war and other emergencies. It was necessary to establish a huge network that could not be operated by a single “central control computer”, so that the whole communication system would not be stopped because of the destruction of some part of the network. More importantly, this network is an autonomous and self-adjusting computer Internet, which allows computers using different storage technologies and operating systems to interconnect. Therefore, the U.S. Department of defense provided funds to the then DARPA to carry out the research, which prompted ARPANET to enter the experimental network from theoretical research.

ARPANET’s further development was due to the discovery by those engaged in this study that it provided a very convenient communication channel. The network was initially connected to only four hosts. In 1970, under the leadership of S. Crocker, NWG completed the original ARPANET host to host communication protocol, known as network control protocol (NCP). In 1972, B. Kahn successfully organized a large-scale ARPANET demonstration at the International Conference on computer communications (ICCC), which was the first public appearance of this new network technology. In the same year, the Internet working group (inwg), headed by V. Cerf, was established to establish Internet communication protocols. The idea of open network structure was put forward by B. Kahn shortly after he came to the advanced research projects agency of the U.S. Department of defense in 1973. In order to meet the needs of open network structure environment, V. Cerf and B. Kahn jointly developed TC P / IP protocol, which was formally proposed in 1974. When ARPANET developed from an experimental network to a practical network, its operation and management was transferred to the defense communications agency (DCA) in 1975.

in 1982, the defense communications agency and the advanced research projects agency decided to use TCP / IP, namely transmission control protocol and network interconnection protocol, as ARPANET communication protocol. This is the first time that it has been made clear that the “Internet” is a collection of interconnected networks. ARPANET, in its first decade of development, was mainly used to promote e-mail, support online discussion groups, allow access to remote databases, and support document delivery between government agencies, companies and universities. ARPANET ceased operation in 1990 after fulfilling its historical mission. NSFNET is working in

Author: zmhuaxia