As you prepare for the CCNA exam, the presentation layer is mostly concerned with data format. It converts the data between different formats so that both the sender and the receiver can use heterogeneous data. For example, mail messages contain various data formats: text, application attachments, video, audio, and graphical signature.

  • The presentation layer on the sending host receives the data payload from the application layer.

  • The presentation layer on the sending host converts the data into a format that is easily transportable over the network.

  • The presentation layer on the receiving host converts the data from the network format back to its native format that can be easily interpreted, used, and displayed by the application layer above.