Which layer of the OSI model does a router operate on?

A router operates at the Network layer of the OSI model. This layer is responsible for routing data packets from one network to another, which is crucial for communication over different networks. Routers use logical addressing (such as IP addresses) to determine the best path for data to travel, which is essential for directing traffic on the internet and within local networks.

At the Network layer, a router encapsulates packets into frames for transmission and decapsulates them when they reach their destination, ensuring that data can traverse various networking environments. By handling functions like packet forwarding and addressing, the Network layer plays a critical role in establishing, maintaining, and terminating network connections. Other layers, such as the Session, Transport, and Application layers, perform different functions and are not primarily focused on the packet-routing capabilities that are fundamental to a router's purpose.