Which device operates at which OSI Layer?- Computer Networks

Network Repeater
connects two segments of your network cable
Repeaters work only at the physical layer of the OSI network model.

Brigde: Reads the outermost section of data on the data packet, to tell where the message is going.
Bridging occurs at the data link layer of the OSI model

Network Router:
route data packets between two networks
reads the information in each packet to tell where it is going.
Routing occur at the Network Layer of OSI model.