Three points, three completely different jobs. Mixing any two of them up is exactly how CG-envelope math and stability analysis go wrong.
Ask someone to point at "the point where the forces act on an airplane" and most people gesture somewhere vaguely near the middle of the wing — as if there's one spot doing all the work. In reality there are three distinct reference points involved, each answering a completely different question, each computed from completely different physics, and each behaving completely differently as the aircraft flies. One comes purely from how much the airplane weighs and where that weight sits. One is where the aerodynamic force happens to act right now, and it moves. One is a deliberately chosen fixed point that engineers use specifically because it doesn't move. Keeping these three straight isn't academic trivia — it's the entire basis for why an airplane is loaded the way it is, and why some loading configurations will make it dangerously uncontrollable.