What layer allows different networks to communicate with each other through routers?

The network layer is responsible for allowing different networks to communicate with each other through routers. This layer handles the routing of packets across multiple networks, ensuring that data is sent from the source to the destination effectively. It manages the addressing and forwarding of data packets, which is crucial when different devices are connected to different internal networks.

Key functions of the network layer include logical addressing, routing, and packet forwarding. When a device sends data to another device located on a different network, the network layer determines the path that the data should take through various routers. This is essential for establishing connections between multiple networks, whether they are local area networks (LANs) or wide area networks (WANs).

The other layers serve different purposes; for instance, the data link layer is focused on node-to-node data transfer, the transport layer ensures complete data transfer and maintains error-checking and flow control, and the application layer is concerned with software applications that provide network services to users.