Which OSI layer handles data formatting and encryption/compression, such as TLS, SSL, and JPEG?

• A. Physical
• B. Data Link
• C. Application
• D. Presentation

Answer: (D)

Data formatting and the ability to encode, compress, or encrypt information are handled where data is prepared for transmission in a form that the receiving system can understand. The Presentation layer sits between the Application and Session layers and is responsible for converting application data into a standard representation, as well as performing encoding/decoding, data transformation, and security operations like encryption and compression. TLS and SSL wrap the payload with encryption to secure it in transit, and JPEG represents a specific data format for images—both illustrate transformations managed at this layer to ensure consistent interpretation across different systems. Other layers focus on signaling, framing, or providing services to applications, not on how data is formatted or secured. So, the correct layer is the Presentation layer.