Unlike automatic hand dryers, manual dryers work when user presses the operating switch. With the advent of modern electronics, every hand dryer is made to be automatic. Manual hand dryers have the same features of automatic hand dryers, while they are operated manually, automatic hand dryers are sensor driven, which makes them intelligent machines.
Usually it will be inconvenient to touch the equipment while your hands are wet and moist. There came the automatic hand dryer that senses when someone places the hand below the hand drying unit.