Process

A process is a sequence of events that bear some similarity but need not always involve the same elements, happen in the same order or produce the same transformation.

In the context of a system, several processes can take place simultaneously. Some can be part of the functioning of the system, while others may be spontanenous, arbitrary or entirely random.

A process differs from a function in how well defined the set of possibly participating elements is and how consistent the output is when given the same inputs.