The impact driver is a high-tech device used in power-driving of hard tasks, like strong-bolts, tough-screws and any hard part of a machine that wouldn’t easily be driven by a regular cordless drill or might be too light for a Hammer drill. This means an impact driver is neither a regular cordless drill nor a Hammer drill. It is simply an Impact Driver. The impact driver is specifically designed for heavy tasks requiring strong torque and beastly handling. They simply feature a motor-driven hammer that repeatedly strikes an anvil that drives the output shaft. As the load increases, they switch from mere spinning to strong impact mode, in which every impact turns the screw a bit farther, while the motor continues to spin and bring in cooling air. They continue increasing the strength of the impact as the surface gets stronger and when it gets light, they gently go back to spinning mode. They are made smart and durable and affordable.