The first stage: The late 1960s to the early 1970s was the embryonic stage of computer network development. Its main feature is to connect small computers into an experimental network in order to increase the computing power and resources of the system. ARPANET, the first long-distance packet switching network, was built by the US Department of Defense in 1969, and a computer network system consisting of a communication network and a resource network was realized for the first time.
ARPANET is a typical representative of this stage, which marks the real emergence of computer networks.
The second stage: The middle and late 1970s is an important stage for the development of local area network (LAN). Its main characteristics are: as a new computer architecture, LAN has begun to enter the industry. LAN technology originates from remote packet-switched communication networks and computer systems with I/O bus structure.
The Palo Alto Research Center of American Xerox Company launched Ethernet, and successfully adopted the basic principles of the ALOHA wireless network system of the University of Hawaii, making it the first local area network with bus competition.
The Computer Research Institute of Cambridge University developed the famous Cambridge Ring. The successful realization of these networks, on the one hand, marks the emergence of local area networks, on the other hand, their Ethernet and ring networks play a navigation role in the future development of local area networks. ?
The third stage: 80' s is the development period of computer local area network. Its main feature is the ability of LAN to realize ISO open system interconnection communication mode protocol completely on hardware.
The integration of computer local area network and its interconnection products makes the technology of local area network interconnection, local area network interconnection with various hosts and local area network interconnection with wide area network more and more mature. The development of integrated service data communication network (ISDN) and intelligent network (IN) indicates the rapid development of local area network.
The fourth stage: from the early 1990s to the present, it is a stage of rapid development of computer networks, characterized by the development of computer networking, collaborative computing capacity and the popularization of the global Internet.
The development of computer has been completely integrated with the network, which embodies the slogan of "network is computer".
At present, the computer network has really entered all walks of life and has been adopted by all walks of life. In addition, with the application of virtual network FDDI and ATM technology, network technology has flourished and quickly entered the market and ordinary people's lives.
Extended data
Computer network is also called computer communication network. The simplest definition of computer network is: a collection of interconnected and autonomous computers for the purpose of enjoying resources.
According to this definition, the early terminal-oriented network was not a computer network, but an online system (because many terminals were not autonomous computers at that time).
However, with the decline of hardware price, many terminals have some intelligence, so the strict boundary between "terminal" and "autonomous computer" is gradually lost. If a microcomputer is used as a terminal, the early terminal-oriented network can also be called a computer network according to the above definition.
In addition, from the logical function point of view, computer network is a collection of computer systems that connect multiple computers with communication lines for the basic purpose of transmitting information. A computer network consists of transmission media and communication equipment.
From the user's point of view, a computer network is defined as having a network operating system that can be automatically managed by users. It calls the resources called by users, and the whole network is like a large computer system, which is transparent to users.
A more general definition is: a system that connects geographically dispersed computer systems and communication equipment with independent functions in different forms by using communication lines, and realizes resource sharing and information transmission by using well-functioning network software and protocols.
The first generation computer network-the online stage of remote terminal;
The second generation computer network-computer network stage;
The third generation of computer networks-the interconnection stage of computer networks;
The fourth generation computer network-Internet and information superhighway stage;
The classification of computer network, like the general classification method of things, can be classified according to the different characteristics of things (that is, the attributes of things). Generally speaking, a computer network is formed by physically (or logically) connecting multiple computers (or other computer network devices) through transmission media and software.
Generally speaking, the composition of computer network basically includes four parts: computer, network operating system, transmission medium (which can be tangible or intangible, such as the transmission medium of wireless network is space) and corresponding application software.
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