Definition - What does Message Passing mean?
Message passing, in computer terms, refers to the sending of a message to a process which can be an object, parallel process, subroutine, function or thread. This message can be used to invoke another process, directly or indirectly. Message passing is especially useful in object-oriented programming and parallel programming when a single message (in the form of a signal, data packet or function) is sent to a recipient.
Techopedia explains Message Passing
Message passing relies on the process and its supporting organization to call the actual code to run. The difference between conventional programming calls by the fact that usual programming procedure calls the process by name instead of a data packet or signal trigger. It is basically communication between two processes, subroutines, or functions within a program. Modern computer software largely uses message passing to implement efficient programming techniques. In networks such as the Internet, where objects may also be working from various computers, the process of message passing plays an important role. Channels are an efficient way to implement message passing in modern systems.