The document discusses simple and compound machines. It provides examples of six simple machines: lever, wheel and axle, inclined plane, wedge, pulley, and screw. Each is defined and an example is given of its location in a house. A compound machine is made of two or more simple machines. Examples provided are a stapler, which uses a wedge and lever, and a can opener, which uses a wheel and axle, wedge, gears, and lever.