How Multirotor Drones Actually Fly · 1/2
No rudder, no ailerons, just spinning rotors
A traditional airplane steers with dedicated control surfaces: a rudder for yaw, ailerons for roll, elevators for pitch. A quadcopter has none of that. It has four (or more) fixed rotors, each pointing straight up, and it steers entirely by changing how fast each individual rotor spins relative to the others. That's the whole trick, and it's a clever one because it needs no moving control surfaces at all, just precise, fast motor speed changes.
To climb, all rotors speed up together, producing more total thrust than the drone's weight. To descend, they all slow down together. Everything else, tilting forward, banking sideways, spinning in place, comes from making some rotors spin faster than others.