Bridging is when you have two wireless access points that transmit data between them, acting as a bridge. So if you have a wireless router, and need internet access far away but can't run a line, you can get a wireless access point and use it to "bridge the gap" between the two locations. The link I provided on the other page is a device you can use for this. It acts as a switch, bridge and access point. There's probably cheaper ones that just act as bridges.