By the term E1, I am assuming you are in Europe?
Bridge:
Basically, in a bridged network, the destination addresses are used differently than from a routed network. Firstly, bridges broadcast a message, asking for where the correct machine. So it sends it to all nodes, which really is not the best thing. Then it waits for the one to reply and then the packet is further processed.
READ: messy and inefficient
Router:
The addresses in packets here actually mean something. The netid is what network (subnet) it is in. The hostid is which node in that network. If you don't understand, I strongly suggest you read about Subnet Masking and IP Addressing. The router doesn't broadcast, it is more efficient, and it doesn't flood the network.
Personally, I wouldn't use a bridge if I could avoid it. I would think that a switch would do better in this case.
one more thing: routers connect *two* or more networks and bridges just segment a network.
Uh I hope that made sense for everyone *grin*
Met
Oh, Neek, Will.. if my rusty self goofed on anything, do correct me :) (though I think I did fine)