Final answer:
The link between two processes to send and receive messages is called message-passing link.
Step-by-step explanation:
The link between two processes P and Q to send and receive messages is called message-passing link. This link allows for the transmission of messages between processes, enabling them to communicate and exchange information.
The message-passing link is a fundamental concept in computer science and is commonly used in parallel and distributed computing systems, where processes on different machines need to communicate with each other.
By using a message-passing link, processes can send messages containing data or instructions to each other, enabling coordination and collaboration between different parts of a system.