A network switch (also called switching hub, bridging hub, officially MAC bridge) is a computer networking device that connects devices together on a computer network by using packet switching to receive, process, and forward data to the destination device.

These are the mostly used types of Switching:

Circuit Switching

When two nodes communicate with each other over a dedicated communication path, it is called Circuit Switching. An important property of circuit switching is the need to set up an end-to-end path before any data can be sent which can either be permanent or temporary.

Applications which use circuit switching may have to go through three phases: Establish a circuit, Transfer of data and Disconnect the circuit. The bandwidth is reserved all the way from sender to receiver and all the data packets follow the same path, thus, ensuring the sequence of data packets are in order.

Packet Switching

The entire message is broken down into smaller transmission units called packets. The switching information is added in the header of each packet and transmitted independently. It is easier for intermediate networking devices to store smaller size packets and they do not take much resources either on carrier path or in the switches’ internal memory.

In packet switched network, first packet of a multi-packet message may be forwarded before the second one has fully arrived, thus reducing delay and improving throughput. Since, there is no fixed bath, different packets can follow different path and thus they may reach to destination out of order.

Message Switching/ Store-and-Forward

In message switching, no physical path is established between sender and receiver in advance. The whole message is treated as a data unit and is transferred in its entirety which contains the entire data being delivered from the source to destination node.

A switch working on message switching first receives the whole message and buffers it until there are resources available to transfer it to the next hop. If the next hop is not having enough resource to accommodate large size message, the message is stored and switch waits. E-mail and voice mail are examples of message switching systems.