Packet switching is a method for sending data whereby the data is divided in packets. Each packet is given a header containing information of the destination. Each packet is forwarded through the network to the destination using this information. At the destination the data has to be reassembled from the received packages.
There are two common packet switching methods in use:
Packet-switched networks were originally designed to overcome the inherent weakness of sending data over the analogue circuit switched network. Circuit switching is not very efficiënt for small messages and the analogue circuits make the data subject to noise and errors.
The biggest packet switched network is the internet. The internet uses the datagram packet switching method. X.25 is based on virtual packet switching.