A multi-point ethernet switch is used to form the network the system operates on and allows all of the devices to communicate with one another.
Switches vary greatly in apperance. However, switches are generally universal.
Shown here are the typical power supplies and connections for both a large and a small ethernet switch.
Cat 5 ethernet cable is used for network connections.
Unlike a router which is used for internet connections, there are no specific in or out ports on a network switch.
As long as the switch has power and a secure connection is made, which is indicated by the corresponding port number and LED on the front panel of the switch, the device is connected to the network.