Groups of computers can be connected in many different configurations.
A simple Local Area Network (LAN) consists of a few computers, which are directly connected to each other.
This allows for high-speed communication between the participating machines, but offers little flexibility for adding more clients. Networks like this are generally confined to a relatively small area, such as a home, business or office.
As more clients are added to the LAN, we require more efficient control of network traffic. This is achieved through the deployment of devices such as Switches and Routers.
A network Switch (S) operates like a central hub through which several computers can communicate at high speed. Computers can send out network broadcasts to inform all other computers of their presence, and high speed peer-to-peer communication is maintained.
Routers can be used to interconnect several LANs together, forming a Wide Area Network (WAN). A Router (R) is used at each connection point between the LANs to control and monitor the passage of data.
The use of Routers allows confinement of network broadcasts to the Local Network only, instead of traversing the entire network, and reducing overall efficiency.
The flow control and management of data as it traverses a physical network is known as Routing. Perhaps the best example of this network structure is the Internet, built upon these same principles; it is a worldwide collection of interconnected.