What is presentation layer and how it is responsible for in the OSI model ?

As the translator, the presentation layer converts the data sent by the application layer of the transmitting node into an acceptable and compatible data format based on the applicable network protocol and architecture.

The presentation layer is layer 6 of the 7-layer Open Systems Interconnection (OSI) model. It is used to present data to the application layer (layer 7) in an accurate, well-defined and standardized format. The presentation layer is sometimes called the syntax layer.

The presentation layer is responsible for the following:

• Data encryption/decryption
• Character/string conversion
• Data compression
• Graphic handling

The presentation layer mainly translates data between the application layer and the network format. Data can be communicated in different formats via different sources. Thus, the presentation layer is responsible for integrating all formats into a standard format for efficient and effective communication. The presentation layer follows data programming structure schemes developed for different languages and provides the real-time syntax required for communication between two objects such as layers, systems or networks. The data format should be acceptable by the next layers; otherwise, the presentation layer may not perform correctly. 

 the presentation layer ensures that the communications passing through are in the appropriate form for the recipient. For example, a presentation layer program may format a file transfer request inbinary code to ensure a successful file transfer. 

The OSI model has seven layers, and each layer performs a specific and supportive communicative task.

As layer six of the OSI model, the presentation layer is primarily responsible for managing two networking characteristics: protocol and architecture. Whereas, protocol defines a standard set of guidelines under which the network operates, the network's architecture determines what protocol applies.