ok general descriptions assuming battery powered all will screw or unscrew if battery powered
drill driver = drill holes and screwdriver capacity
hammer drill =will drill including hammer action for hard masonry holes and screw driving
driver= usually only very slow speed somtimes with a clutch very compact hex drive
impact driver = large screws to smaller screws and sometimes further fuctions but only ever via a hex drive
as an aside many a person will use a mains drill to screw until the drill burns out 'they get sick off screws stripping or heads turning off 'wood splitting ruining work all through lack off control not knowing any better but worse still frustrating and discouraging further experimentation
