Which layer of the OSI model directly interacts with the user?

The application layer is the topmost layer of the OSI model and serves as the interface between the user and the underlying network services. This layer is responsible for providing network services directly to the user and enables applications to communicate over the network. When users interact with software applications—such as web browsers, email clients, or file transfer programs—they are actually engaging with protocols and services provided by the application layer.

This layer encompasses protocols that operate for user applications, such as HTTP, FTP, and SMTP, which handle tasks like web browsing, file transfers, and email transmission. Since it interfaces directly with user applications, it is designed to be user-friendly and relevant to end-user tasks.

In contrast, the transport layer, network layer, and session layer play essential roles in managing data transmission and ensuring sessions are maintained, but they do not have a direct interface with the user. Instead, they function behind the scenes to facilitate communication between applications and ensure data integrity, routing, and session management.