Which layer of the TCP/IP model interfaces between applications and the network?

The Application Layer is the correct choice because it serves as the interface between user applications and the underlying network protocols. It enables software applications to communicate over the network by providing the necessary protocols and functions for data exchange. This layer handles high-level protocols like HTTP, FTP, SMTP, and DNS, which are essential for web browsing, file transfer, email transmission, and domain name resolution.

In contrast, the other layers in the TCP/IP model serve different purposes. The Transport Layer is responsible for end-to-end communication and data flow control, ensuring reliable or unreliable data transfer depending on the protocol used (like TCP or UDP). The Internet Layer handles the routing of data packets across the network, managing logical addressing and delivering packets from the source to the destination. The Network Access Layer (or Link Layer) interfaces directly with the physical network hardware and is responsible for defining protocols for the hardware addressing and the protocols used to establish a connection on the physical network medium.

Thus, the Application Layer specifically focuses on providing services directly to the user applications, making it the correct response to the question regarding the interface between applications and the network.