A device that makes work easier by changing the size or direction of force is called a machine.

Here's why:

* Changing the Size of Force: Machines can multiply force, allowing you to exert less force to accomplish a task. For example, a lever allows you to use less force to lift a heavy object.

* Changing the Direction of Force: Machines can change the direction of force. For example, a pulley system allows you to pull down on a rope to lift an object upwards.

Examples of machines:

* Simple machines: Lever, pulley, wheel and axle, inclined plane, wedge, screw

* Complex machines: Cars, bicycles, computers

While the term "machine" is broad, it encompasses any device that helps us accomplish work more efficiently by altering the force needed.