Switches vs Bridges

 A switch port has its own collision domain; a bridge has one large collision domain for all ports. Bridges are software based where as switches are hardware based (ASICs chip). A switch can deal with two or more dissimilar networks where as a bridge can only deal only with identical networks. Switches operate on the data link layer while bridges operate on the network layer. A switch has one many spanning tree instances while a bridge only has on spanning tree.