@jblackburn A bridge is a medium that allows two different types of networking protocols to communicate (ether and virtual, WiFi ether switch and router... etc) at the layer 2 level.
The intended use of a bridge is:
Physical iface (Ether, WiFi, DSL...) <-> 2.Specific VLAN tag traffic iface (on the physical NIC) <-> 3. Switch <-> 4.Bridge <-> 5. Other ifaceA switch is different in that it is an actual electronic switching circuit. A bridge doesn't switch anything by itself, it needs software to forward packets.