Process to Process Delivery

Why
Process to Process Delivery is important because it is one of the critial services that transport layer protocols such as TCP and UDP must provide in order to be useful to applications running on host systems

What
Process to process delivery is the service that performs the multiplexing and demultiplexing processes.

Multiplexing
This is the act of gathering together segments and filling in the correct header fields in order to ensure successful communication between two processes

Demultiplexing
This is the act of interpreting a segment when it arrives and sending the segment to the correct process