What is Computer Network
A computer network, often simply referred to as a network, is a collection of computers and devices interconnected by communications channels that facilitate communications and allows sharing of resources and information among interconnected devices.
Networks may be classified according to a wide variety of characteristics such as medium used to transport the data, communications protocol used, scale, topology, organizational scope, etc.
Source:
http://kingofnetworking.weebly.com
Common Type of Network
Local Area Network - LAN
Source:
furiousnet.com
A computer network that spans a relatively small area. Most LANs are confined to a single building or group of buildings. However, one LAN can be connected to other LANs over any distance via telephone lines and radio waves.
Most LANs connect workstations and personal computers. Each node (Individual computer) in a LAN has its own CPU with which it executes programs, but it also is able to access data and devices anywhere on the LAN. This means that many users can share expensive devices, such as laser printer, as well as data. Users can also use the LAN to communicate with each other, by sending e-mail or engaging in chat sessions.
Metropolitan Area Network - MAN
Source:
readanddigest.com
Metropolitan Area Network is a network which connects the users with computer resources in a geographical region which is larger than LAN or covered by a large local area network but smaller than the area enclosed by WAN. This network is also employed to the linkage of various local area networks through connecting them with the strong lines. There are three major technologies are used to develop the MAN (Metropolitan Area Network) that include ATM (Asynchronous Transfer Mode), SMDS (switched multi megabit data service) and FDDI (fibre distribution data interface). General example of MAN derived service includes cable connections for television in different blocks of any city.
Wide Area Network - WAN
Source:
furiousnet.com
A wide are network (WAN) is a computer network that covers a broad area
(i.e. any network whose communications links cross metropolitan,
regional, or national boundaries), This is in contrast (Advance) to LAN
(Local Area Network), which are usually limited to a room, building,
campus.
WANs are used to connect LANs and other types of networks together, so that users and computers in one location can communicate in other locatins. Many WANs are built for one particular organization and are private. Others, built by Internet service providers, provide connection s from an organizations LAN to the internet. WANs are often built using leased lines. At each end of the leased line, a router connects to the LAN on one side and a hub within the WAN on the other.
Best example of WAN is the Internet.