Q & A on Switches and routers Q: If I have a big switch, do I also need a router? A: Although they are both electronic devices, switches and routers perform quite different functions. Switch In general, a switch can be thought of as the central component of a single network -- it interconnects computers and passes frames among them. The chief difference between a switch and a hub lies in speed. A hub only allows one computer to transmit at a time, but a switch permits simultaneous communication between disjoint pairs of computers. Router A router interconnects two or more _networks_, and passes IP traffic among them. The networks can be heterogeneous (i.e., the frame formats and addressing can differ). For example, a router can interconnect an Ethernet and an FDDI ring. So, the answer is that if all you need is one large, homogeneous network, a switch will suffice (assuming you can fine one with enough capacity). If you have multiple, heterogeneous networks, a router is required.