A drill is a small machine you hold in your hand. You use it to drill holes
in things, or to screw
things together or unscrew them. You can change what you can do with a drill by changing the bit
that spins around at the end of the drill. Most drill bits are just a thin, sharp
rod that spins around to make holes, but some bits are the same as the end of a screwdriver
that you can use on different sized screws.