If you want to connect only one computer to the powerline network, you need a node. If you plan to connect a group of computers currently not HomePlug ready to the powerline network, you need a bridge. The Ethernet powerline bridge can be used as either a node or bridge. It is designed as a bridge in default; the only way to turn it off is to install the utility software that comes with the unit. That will turn the bridge into a node. If used as bridge, there is a limitation of having only two bridges on the same powerline network.