Buffing/polishing 101.
The buffer has a straight spindle that runs in the 2,000 RPM range. Great for cutting down a rough paint job, over spray or in some cases oxidation if it's not to bad. Easy to cut through the color coat or burn off an edge.
The random orbital has a small throw, about .313, on the end of it's spindle and a second bearing on the bonnet and the small crank that this creates. In other words you can spin the bonnet and not turn the motor. If you trigger the orbital the bonnet will not rotate if you have enough pressure on the bonnet. It will jump like crazy though. As you release that pressure you will get rotation of the whole assembly both axially and radial. When you release the trigger the bonnet will coast to a stop long after the spindle stops. Smaller bearing, less friction surface is the reason.
The surface will not get hot as quick because you can control the amount of rotation and orbits it generates. It also leaves very short arcs rather that the swirl marks from a buffer that I'm sure you've all seen.
Some side notes, it will wind your watch very tight, so take it off. You also need to take off your rings and belt buckle and wear sweats not Levies. The wool bonnets can and do catch rings and watches. The newer foam, dimpled bonnets are the best ever. Run the cord up you arm and over your shoulder, this lessens the chance of winding it up in the bonnet. It also keeps it from dragging on the top of the fenders when you do the hood and trunk. Even with an orbital the bonnet should always be leaving the edge/corner, not coming to it. This buffing/polishing compound is high grade mud, so wear glasses or goggles.
Don’t be afraid to wash it with lots of water a couple of times before you start using a dry rag to polish it, the compound will come back to haunt you when you least need the aggravation. Some of the polishing compounds won’t give you any problems, but why take a chance?