Network Sharing

• Only one computer can apply a signal to the network cable at any one time. This is because data passes as an electric charge on a wire. The current possesses all the length of the wire in an instant. This means that several messages on the wire at the same time would merge and become meaningless. If a computer sends a long stream of data over a network, all other computers connected to the same cable would be locked out. For this reason, data travels in small segments. The enables other computers to pass their data over the wire between transmissions of the smaller segments of the original transmission. Segments of data need to be carried in a structure. That structure is called a packet.
  
  

Data Packets

• Efficient use of cable configures networks as an interconnecting series of wires. Data packets have to follow a path across several wires, called links, in order to reach their destinations. This journey requires the data packet to be addressed, like a letter passing through the postal system. The packet not only carries its destination address, but also the address of its point of origin. This enables the sender to be notified of any errors encountered during transmission. It also lets the receiver know where to send any replies.
  
  

Switching

• A data packet would not be able to reach its destination without network devices made to forward data across networks. These devices are called hubs, switches and routers. Their purpose is to pass on data packets to the next link in their route. These network devices join lengths of cable into a packet switched network.
  
  

Importance

• Packet switching is the most efficient method of joining many points together by cable. An alternative method is called circuit switching, which forms a bridge between two cables. This method blocks, or misdirects, any messages traveling down the same cable but not destined for the connected cable.