A computer network is a set of computers and computerized peripherals connected together for the purpose of sharing resources.
Computers may connect to each other by wired media or wireless media.
Types of Networks:
Generally networks are classified based on their geographical span -
1) LAN (Local Area Network):
A local area network (LAN) is a computer network that interconnects computers within a limited area such as a home, school, computer laboratory, or office building, using network media. In a LAN computers in the network can be from few to hundreds.
LAN provides a useful way of sharing resources between end users. Resources like Printers, File Servers, Scanners and internet is easy sharable among computers. LAN can be wired or wireless or in both forms at once.
The most popular local area networking protocol today is Ethernet.
2) MAN (Metropolitan Area Network):
A metropolitan area network (MAN) is computer network larger than a local area network, covering an area of city or a large campus. It is used by big organization to connect all of its offices within city.
A Metropolitan Area Networks bridges a number of LAN with a fiber-optical links which act as a backbone, and provides services similar to what Internet Service Provider (ISP) provide to Wide Area Networks and the Internet.
2) WAN (Wide Area Network):
A wide area network (WAN) is a network that covers a broad area (i.e., any telecommunications network that links across metropolitan, regional, national or international boundaries) using telephone systems, fiber-optic cables, and satellite links or leased lines. The Internet is also a WAN which is the largest WAN in a world.