What encapsulation means in networking?

• A. The IP layer removes headers
• B. Data is transmitted without headers
• C. Every protocol adds its own header to the packet, treating it as a payload
• D. The data link layer adds a trailer

Answer: (C)

Encapsulation is the process where data from a higher layer is wrapped with protocol-specific information at each lower layer as it moves down the stack. Each layer takes the data it receives and adds its own header (and sometimes a trailer), turning it into a new protocol data unit to be passed to the next layer. The original data becomes the payload for the next layer, and only at the destination are these headers removed in reverse order (decapsulation) to recover the original data. This mechanism allows proper addressing, routing, sequencing, and error detection across the network. That’s why the best description is that every protocol adds its own header to the packet, treating what came before as the payload. The other statements don’t fit because headers aren’t removed during encapsulation at the IP layer, data isn’t transmitted without headers, and while a trailer can accompany a frame, encapsulation centers on headers added by each layer rather than just a trailer.