Here's why:

* Force and Work: Machines help us do work by changing the amount of force we need to apply or the direction in which we apply it.

* Types of Machines: There are many types of machines, including:

* Simple Machines: These are basic machines like levers, pulleys, wedges, wheels and axles, inclined planes, and screws.

* Complex Machines: These are more sophisticated machines that combine multiple simple machines, like cars, bicycles, and cranes.

Key Point: While machines can make work easier, they don't actually reduce the total amount of work required. They just change the way that work is done.