The history of networking can be broadly divided into three phases.

 Mainframe Networks.

 Minicomputer Networks.

 PC Networks.

Virtually all early PC networks used the shared bandwidth model. Some of the various LAN types that were developed are:

 ETHERNET

This was invented at the famed Xerox Palo Alto Research Center (PARC). Ethernet is basically a shared cable system. If the wire is not in use, the host can send data on it. If a collision occurs, the senders back off and wait for a random time period before trying again.

This concept works best with a small number of computers at bursty speeds. As the network grows, the number of collisions increases and reduces the overall throughput. The initial form of Ethernet works at 10 Mbps, Fast Ethernet works at 100 Mbps and Gigabit Ethernet at 1000 Mbps.

  TOKEN RING