Which device is used to connect different networks and route traffic between them?

The device used to connect different networks and route traffic between them is a router. Routers operate at the network layer of the OSI model and are responsible for directing data packets between various networks, determining the best paths for data transmission based on the current network traffic and topology.

Routers can handle different types of network protocols and can also integrate features like NAT (Network Address Translation) and firewall functionality, which are crucial for managing traffic between local networks and the internet. This ability makes routers essential for establishing connectivity not only within a local area network (LAN) but also across wide area networks (WANs).

In contrast, a switch is designed to connect devices within the same network and operates at the data link layer, focusing on forwarding frames based on MAC addresses without routing capabilities needed for different networks. A hub functions similarly to a switch but operates at a more basic level, simply forwarding signals to all ports without filtering or directing traffic. A repeater is used to extend the range of a network by amplifying signals but does not manage or route traffic between networks.