A Network of Computers is a group of computers connected in some fashion in order to share resources. Networks with enhanced storage and server-based processing power provide users with greater functionality and security than independent or stand-alone machines.

Networks ca be classified based on:

Physical size

They can be classified as local area networks (LANs), metropolitan area networks (MANs), or wide area networks (WANs).

Local area network (LAN) is most common type of network, a network that covers a limited area like a house or school.

The largest type of network is a Wide Area Network (WAN), a network that extends over a large geographic area and is composed of many, many LANs.

Topology

Topologies (the manner and complexity of interconnections) include the bus topology, star topology, ring topology, and mesh topology.

Security

Networks can be based on workgroups, in which all machines control their own security, or they can be based on servers (such as domain-based Microsoft Windows Server networks).

Network architecture

For example, networks can be classified as Ethernet, Token Ring, or Fiber Distributed Data Interface (FDDI) networks.

Primary Protocol

Networks can be classified as Internet Protocol (IP) networks, Internetwork Packet Exchange (IPX) networks, Systems Network Architecture (SNA) networks, and so on.

TCP/IP Networking

In TCP/IP networking, a network is a group of hosts with the same network ID. Multiple networks can be combined using routers to form an internetwork. Each network in an internetwork can be referred to as a subnetwork.