Used on a variety of materials, depending on the type of blade used. Some blades can cut through wood and metal, which is ideal when cutting through wood that might have nails in it.
Uses a straight blade that operates with a back and forth motion. Some saws may have an orbital action, and some models may let you choose between orbital and linear action. A third option is a swing action, which offers a smoother and faster cutting action.
Blade action usually goes to about 2,000 strokes per minute, but some pro models go higher.