What is the term for the process of adding extra headers and trailers to data before sending it over the network?

The term for the process of adding extra headers and trailers to data before sending it over the network is encapsulation. This is a fundamental concept in networking and data communication. During encapsulation, data at a higher level (like application data) is wrapped in headers and trailers as it moves down through the layers of the OSI or TCP/IP model.

For instance, when data is prepared to be sent over a network, it goes through several layers, starting from the application layer. At each layer, specific information such as source and destination addresses, control information, error-checking codes, and other metadata is added, which helps in routing, delivering, and ensuring the integrity of the data across the network.

Encapsulation not only organizes the data properly but also allows different types of data (like TCP segments, IP packets, Ethernet frames) to be transmitted correctly according to the rules of each protocol layer. This process is key for enabling the effective communication necessary for networks to function properly.