In a network, what device connects different subnetworks?

The correct answer is a router, which is designed specifically for connecting different subnetworks within larger networks. Routers operate at the network layer of the OSI model and are responsible for determining the best path for data packets to travel from one network to another.

Routers facilitate communication between separate IP address spaces, making them essential in segmenting networks, while effectively managing traffic flow and providing necessary services such as network address translation (NAT) and dynamic routing.

Switches operate at the data link layer and are used to manage traffic within the same network or subnetwork by connecting devices, but they do not inherently connect different subnetworks. Hubs are basic networking devices that transmit data packets to all connected devices in a network without filtering or directing traffic, making them inefficient for subnetworks. Modems, meanwhile, are used primarily to connect a local network to the internet by converting digital signals to analog signals and vice versa, rather than connecting different subnetworks.