A "central hub" wired to every computer and network device in an Ethernet. In the home and small office, an oem ethernet switchis built into the router. all Ethernet devices sense the speed of the connection and transmit at the highest common denominator. lthough an Ethernet switch is sometimes called a hub, there is a huge difference between a true hub and switch. Most Ethernet hubs have been replaced with switches, vastly improving network throughput.