It is known that one of the most significant achievements of mankind in the last century was the creation and rapid development of information technologies - technologies that allow, using computers and various types of computer networks, to store, process, convert and transmit huge amounts of information. It is worth noting that such a rapid leap in information of mankind became possible only after computer communication networks were created.
All types of computer networks are a set of computers distributed over a certain territory and interconnected by specialized channels that allow data transfer. To date, computer networks are widespread, various types of computer networks operate around the world and interact with each other. A modern understanding of the signs of networks has led to the emergence of classification according to territorial criteria. According to this classification, the following types of computer networks are distinguished:
Global Area Network (GAN) - global networks that combine computers and networks located in different parts of the world.
Wide Area Network (WAN) - large-scale networks that combine computer networks at the level of continents and states;
Metropolitan Area Network (MAN) - long-distance networks connecting computers and networks within regions and other administrative units;
Local Area Network (LAN) - local area networks that involve the union of computers located at relatively short distances - for example, within the same building.
WAN and MAN are regional networks. It is worth noting that today the separation of computer networks into WAN and MAN is very conditional, since now almost every regional network is part of a global network.
Many organizations that are interested in providing a high level of information protection from encroachments from the outside (for example, military, banks, etc.) create their own networks, which are called corporate. The corporate network can include tens of thousands of computers that are located at a considerable distance from each other, for example, in different countries.
The most common in the world numerically are local computer networks.
The main distinguishing feature of local networks is the ability to connect computers with a cable, without resorting to channels for transmitting data used by global networks (telephone network, fiber optic cable, radio, etc.). Since computers are located close to each other, to create a network it is enough to connect them with a cable and configure accordingly. The network integration of computers into an in-house computer network gives its owners a lot of advantages.
Types of local computer networks are most often divided by topology - the way computers are connected to each other. Topology is the most important characteristic of local networks, since it is by the method of connection that the most important indicators, represented by performance and reliability of operation, are determined.
Networks made according to the star topology have the greatest advantages - all other computers in the network are connected to one central source.
There are networks made according to the “ring” topology - all computers communicate with each other sequentially and eventually form something resembling a ring.
The third type of topology by which local computer networks are created is the bus topology - all network computers are connected to one cable - the data bus.
Computer networks, the principles of their work, protocols, and hardware components are constantly being improved and developed.