What layer of the OSI model is responsible for establishing, managing, and terminating sessions between applications?

The layer of the OSI model responsible for establishing, managing, and terminating sessions between applications is the Session layer. This layer plays a critical role in enabling communication sessions between two systems. It establishes the rules for the communication, including how a session is initiated, maintained, and terminated. This is significant because it ensures that dialogues between applications are properly coordinated, which is particularly important in scenarios where long-standing connections or continuous data exchanges are involved.

In contrast, the Transport layer primarily focuses on end-to-end communication and error recovery but does not manage sessions directly. The Network layer handles the routing of packets across different networks and is more concerned with logical addressing. The Data Link layer is responsible for node-to-node data transfer and error detection at the physical level, rather than application-level sessions. Each layer of the OSI model has distinct responsibilities, making the Session layer uniquely qualified for session management.