Most screwdrivers are operated manually, but there are some that use an electric or other motor to rotate the bit. They are used to drive screws quickly into various materials. There are different types of driver bits that let a drill drive different types of screws. The bit can be removed and swapped with another bit of a different shape. Many types of drills are able to be used as power screwdrivers. The best have a control over how much torque force is used, which allows the screws to be tightened to a specific level.