Welcome to Autopia AutoNova.
I'll just assume you placed this thread in the 1Z forum by accident

so I'll move it to AU for you.
For your question, I highly suggest either checking out the Learn! link at the top, buying the Autopia eBook, or both. Also, since you are asking about orbital polishers, I
highly recommend clicking the PC Accessorizing link in my signature and then looking in that thread for the 2 links I have provided to GeekySteve's excellent writeups on the
Porter Cable orbital over at Roadfly. He explains everything for beginners looking at polishing machines.