What is the definition of a machine?

A machine can indeed be defined broadly as any tool that assists people in doing work. This definition incorporates a wide range of devices, from simple hand tools like levers and pulleys to complex machinery like engines and computers. The key aspect of this definition is the emphasis on the machine's role in facilitating the accomplishment of tasks, thereby allowing humans to exert their effort more effectively and efficiently.

While other definitions may focus on specific aspects of machines—such as reducing the amount of work, transforming energy, or accomplishing tasks—they all stem from the fundamental component that machines serve to aid human activity. For example, reducing the amount of work highlights a machine's efficiency, but it does not encompass every tool's functionality; many machines allow for the performance of tasks that would otherwise be impossible or extremely difficult without them.

Thus, this broad definition captures the essence of what a machine is in the context of simple machines and their applications across various fields and scenarios.