Question: What's the difference between a hub and a switch?

Solution: Everything sent through an ethernet network is basically cut into small bits of data known as packets. The computer wishing to send information gives the packets an address, and sends them down the cable.

If the packet comes to a hub, then the hub copies the packet and sends it to every other port it has. Once one of the packets gets to the proper destination, the intended recipient sees their address on the packet and accepts it. Those that do not see their address on a packet, discard. With a hub, if systems try to send on the line at the same time then a data collision occurs and the packets must be resubmitted.

A switch is a bit smarter. It learns the addresses of the individual systems. When a packet comes to it, the switch takes a look at the address on it and sends the packet to it's proper destination without sending it to everyone else too. Due to these improvements over the hub, the switch often performs better where high network throughput is desired.