Switches
A network switch (also called switching hub, bridging hub, and, by the IEEE, MAC bridge) is networking hardware that connects devices on a computer network by using packet switching to receive and forward data to the destination device.
A network switch is a multiport network bridge that uses MAC addresses to forward data at the data link layer (layer 2) of the OSI model.
Some switches can also forward data at the network layer (layer 3) by additionally incorporating routing functionality.
Such switches are commonly known as layer-3 switches or multilayer switches.