What device primarily connects multiple networks together?

A router is the device primarily responsible for connecting multiple networks together. It functions at the network layer of the OSI model and is designed to route data between different networks, such as connecting a local area network (LAN) to a wide area network (WAN) or the internet. Routers use IP addresses to determine the best path for data to travel, making them essential for managing traffic and ensuring that data packets reach their intended destinations across diverse networks.

In contrast, a switch primarily operates within a single network, facilitating communication between devices in a local area network by forwarding data based on MAC addresses. Hubs, which are less common now, simply repeat the incoming data signal to all ports without any intelligence about where the data should go. Access points serve as communication devices that allow wireless clients to connect to a wired network but do not connect multiple networks themselves. Thus, the unique role of a router in facilitating inter-network communication clearly defines its primary purpose in networking.