Drills are tools that have motors which rotate drill bits by a chuck while the user is pressing it against the target material. You can install a screwdriver tip to turn screws as well with a drill. Important parts of drills include an on/off trigger , a handle and a chuck that holds the drill bit. Now a days most of the drills are equipped with reversing switch for changing the rotation. Drills are used in metalworking ,woodworking, do-it-yourself projects and construction. Drills have many types like electric drills and divide by corded and cordless drills and pneumatic drills that are powered with compressed air. There are also drills with a percussive action like impact drills and rotary hammer drills that are used in hard materials such as masonry witch include stone , brick and concrete.