Dual Action polishers are characterized by the motion of the head. It spins on a central spindle, and this spindle rotates around an eccentric offset. A good metaphor for a dual action polisher is the earth's orbit. The earth itself spins and it also orbits around the sun.
The Dual Action Polisher cleans, polishes and waxes with a motion like that of the human hand - only at super-human speed! The result is a machine that is completely stable, with no tendency to "run away" from the operator. The smooth, hand-like action safeguards against surface damage.