Hi,

A bridge is is an Intermediate system used to connect two LANs that use similar LAN Protocols.The bridge acts as an address filter,picking up packets from one LAN that are intended for a destination to another LAN and passing those packets on.It operates at Layer2 of the OSI Model.

A router used to connect two networks that may or may not be similar.Router employs an internet protocol present in each router and each end system of the network.It operates at Layer3 of the OSI Model.