Final answer:
The boundary between a computerized system and its users is called the system boundary, a term essential for understanding human-software interactions and decision-making processes supported by software.
Step-by-step explanation:
The boundary between the computerized portion of the application/system and the users who operate the system is commonly referred to as the system boundary. This concept is crucial in understanding how human-software interactions occur, especially the decision-making processes of workers as they are supported by the software system. At the physical level, engineers view computers as devices undergoing electronic changes. At the design level, programmers see computers as machines running programs. Finally, at the commonsense level, users see computers as tools for tasks like word processing or solving equations.