*Stolen from detailing world
The random orbit nature of a dual action polisher means that it generates far less heat than a rotary polisher. It is a more gentle tool so correction work typically takes longer. However it is also safer to use and easier to learn which makes it the ideal beginners’ tool.
Owing to their nature, where the pad spins on a constant orbit, a rotary polisher can develop significant heat on the paintwork which can lead to paint burns in the hands of an inexperienced user.
By contrast, a dual action polisher is a much safer tool to simply pick up and use. By dual action, it means that the pad not only spins in a circle, but it also oscillates. This results in a random orbit movement of the pad – sometimes such polishes are referred to as “Random-Orbit” polishers (RO polishers) for this reason. The diagram highlights the difference between the pad motion of a rotary and a dual action polisher
Basically a DA is a lot safer and doesn't rotate constantly over the same area, it's almost impossible to damage the paint using one of these. Also on your steps above, I would go over the car with Tardis before I used a clay bar, it's much much easier doing it like that, it will remove most of the shit then you can go over it with the bar after.