Which layer of the OSI model is primarily concerned with end-user applications?

The Application layer of the OSI model is primarily focused on providing network services directly to end-user applications. It enables software applications to communicate over a network, facilitating the interaction and exchange of data between various applications and the underlying network protocols. This layer encompasses a variety of protocols and services that support user-level functions, such as file transfers, email, and web browsing.

While the Transport layer is concerned with the end-to-end communication and reliability of data transmission, it operates below the Application layer and does not interact directly with end-user applications. The Session layer manages sessions between applications, but again, it does not engage directly with the applications themselves. The Data Link layer is responsible for node-to-node data transfer and error detection at a much lower level and does not involve end-user applications. Thus, the Application layer serves as the critical interface for users to interact with the network through their software applications.