Connecting to the LAN using USB
The USB port on most routers is not actually for connecting computers. It’s for making storage devices (such as USB drives) accessible over the network. Many modern computers (such as the new Macs) do not have an Ethernet port. So the only way for them to connect to a network is either over the wireless, or using a USB-to-Ethernet adapter. But note that for the Mac to recognize the network connection over USB, the USB adapter has to be plugged in with a live Ethernet connection. If the Ethernet is turned on after the adapter is plugged in, the Mac won’t recognize the connection.