Packet Switching:
This is one of recent techniques of switching. Packet switching was originally developed for use by ARPA network by the Defence Department of US. According to this method, each message is broken into packets of approsimately 1000 bits each. Each packet carries information about its origin and destination Packets are stored and forwarded by means of computers in a steady stream, but not in any order. Specially designed computers sort out the packets at each node in the transmission network and retransmit them along the best path to their destination, where they are put in the right sequence for decoding. Because of the standard size of packets, transmission is highly efficient and less prone to error. As a result, economies are effected which benefit the end user. -Packet switching is the technology used in value-added networks like Tymnet and Telenet, which provide libraries with connections to many database search services.
The advantages of packet switching include transmission economies because of shared utilization, high quality, error reduced service, and the facilities for speed changing and procedures conversion thus allowing communication between different types of terminals and the interconnection of networks.