What is driver? What is driver? One that drives, as the operator of a motor vehicle.A tool, such as a screwdriver or hammer, that is used for imparting forceful pressure on another object.A machine part that transmits motion or power to another part.Computer Science A piece of software that enables a computer to communicate with a peripheral device.Sports A golf club with a wide head and a long shaft, used for making long shots from the tee.Nautical A jib-headed spanker.