Drill is a tool used to bore holes into a variety of materials. These materials range from soft soil to hard rock, metal, plastics, and concrete. Drills are widely used to bore holes into wood or metal so screws or other fasteners can be inserted. Construction workers use drills to break up pavement and to dig foundations for buildings. Energy companies rely on drills to dig for oil and natural gas and to get rock samples. Dentists use small air-powered or electric drills to remove tooth decay.