Cleaner Wax/All-In-One/AIO = Products that most detailers and forum members think of when referring to a product that "Cleans, Polishes, Protects"
Examples: HD Speed, Griot's Finishing Sealant, D166 Ultra Polishing Wax
One Step = Products designed to fill the gap between a heavy correction compound and a fine finishing polish. They generally will not cut as much as a heavy correction compound nor will they finish to the level of an extremely fine finishing polish. The benefit of a 1-step compound/polish is being able to have ONE product that's cutting/finishing capabilities can be tailored depending on the goal of the 1-step. If finish is more important, use a foam polishing pad. Or if you're looking for more cut, you can pair it with microfiber or foam heavy cutting pads. They are generally body shop safe and don't contain and waxes, silicones, or fillers.
Examples: Boss Correcting Cream, HD Adapt, Scholl Concepts S20 Black, Sonax Cut & Finish.