The document discusses several simple machines: pulleys, which support cable or belt movement along their circumference; screws or bolts, which are fasteners with helical ridges; levers, which are rigid rods pivoted at a fixed point; wedges, which are used to push objects apart and are made of two inclined planes; wheels and axles, where an axle allows a wheel to turn to move objects; and inclined planes, which are tilted flat surfaces used to raise or lower loads. Each machine is defined and examples are provided.
