Which layer of the OSI model does a switch primarily operate at?

A switch primarily operates at the Data Link layer of the OSI model. This layer, which is the second layer in the OSI hierarchy, is responsible for node-to-node data transfer and manages how data packets are formatted for transmission over the physical medium. Switches use MAC addresses to determine the destination of a data frame and make forwarding decisions based on this information. This functionality allows switches to create a separate collision domain for each connected device, thus enhancing overall network efficiency.

In contrast, the Network layer is responsible for routing packets across different networks, the Transport layer focuses on end-to-end connection and reliability of data transmission, and the Session layer manages sessions or connections between applications. These layers are essential for different aspects of networking, but they do not perform the specific data handling tasks that a switch is designed for at the Data Link layer.