OSI for CCNA Layer 7: Application
The CCNA exam requires knowledge of the OSI reference model's application layer. This layer represents the various network applications such as e-mail reader, Web browser, Hypertext Transfer Protocol (HTTP), File Transfer Protocol (FTP), and Network File System (NFS).
The application layer provides a user interface and processes network data.
The application layer on the sending host produces the network data to be transmitted from the sender host.
The application layer on the receiving host consumes the network data produced and transmitted by the sender host.