Router: A router is a device that connects multiple networks together and forwards data packets between them.

Switch: A switch is a device that connects multiple devices within a network and forwards data packets between them.

Hub: A hub is a device that connects multiple devices within a network but does not forward data packets between them.

Bridge: A bridge is a device that connects multiple LANs together and forwards data packets between them.

Modem: A modem is a device that modulates and demodulates signals to convert digital data into analog signals for transmission over telephone or cable lines.