Application layer, Presentation layer, Session Layer,Transport Layer,Network Layer,Datalink Layer,Physical Layer
The application layer represents the various network application at the user end such as ftp,http,email nfs and etc.
This provides a interface to the users and process network data. Here in this layer sending host produces the network data to be transmitted from the sender host.
And the receiving host consumes the network data produced and transmitted by the sender host.
Layer 6 of osi model is Presentation layer. this is mostly concerned with data format. Presentation layer converts the data between the sender and receiver end to the different formats. So that both end users can use the heterogeneous data.
Presentation layer on the sending host receives the data from the application layer and converts the data into easily transportable format over the network.
And finally the presentation layer on the receiving host converts the data from the network format to original format that can be easily interpreted,used, and displayed by the application layer.
Session layer maintain the data about the session established between the computer hosts which is running the network application on both sending and receiving end.
Initially it opens and maintain the logical communication channel between application running hosts on both sending and recieving end and also handles the authentication for the applications before initializing process if need.