What is Computer Network ?





A computer network is a collection of computers which use a series of standard computer communication protocols to share information and resources between the various nodes in the system. A computer network consists of all the computers belonging to a single network, a large number of network devices, a few physical links and some physical connections which form an internet. There are two types of networks, primary and secondary, which include Ethernet, Fibre Channel, Infrared, Token Ring and Layer 2 Switching.

Primary Computer Network

The primary Computer network consists of those computers which are connected directly to the central processing unit (CPU) or the central processing unit network (CPU/CPNI). The network devices used for this purpose are hubs that act as the nodes of a computer network and have multiple interfaces connected to other nodes. The different type of network comprises those who are connected through routers or firewalls, which are used to connect to other computers in various networks. An IP address can be assigned to a computer on the primary network, and then it is assigned to a network device that can be an interface such as a router, a switch or a gateway. All these networks are used for various purposes such as creating a secure link between the networks, monitoring security and maintenance of the networks.

Secondary Computer Network

The secondary Computer network consists of the computers in the secondary network. They are usually connected to the primary network through the internet. This type of network contains many different types of networking devices including Ethernet cabling, Fibre Channel cabling, Infrared cabling, Token Ring cabling and Layer 2 Switching cabling. In the case of Ethernet, the Ethernet cable is used for connecting the computers to the Ethernet switch, which then acts as a router. The Fibre Channel cabling is used for connecting the computers in the secondary network. In the case of Infrared, the infrared cables are used for connecting the computers to each other through a modem. In the case of Token Ring, the devices are connected through an ethernet card.





There Are many type of Computer network LAN, WAN, MAN, SAN, CAN, PAN And GAN.





LAN-Local area Network





A local area network (LAN) is simply a network which interconnects multiple computers in a limited geographical area, like a house, office, laboratory, school, college or university building. This type of network is used for connecting several computers. It considered to be one of the fastest ways to communicate with computers and share files without having to depend on any external third party.





LANs usually have small scale networks with limited bandwidth. The LAN network of a residential household consists of a single computer, which acts as the central location from where data is exchanged between the computers in the network.





The cost of Internet service can vary depending on the speed of the connection. Generally speaking, dial-up is the cheapest and broadband is the most expensive. To help reduce the cost of Internet access, it is advisable to limit the number of computers that will be connected to the LAN. Although this may seem to be limiting, in reality, the LAN is used not just for sharing files but also to provide the Internet service to a specific area or a particular group of people. This computer network basically for the local area or building.





WAN- Wide area network



