As mentioned earlier in this section, the throttle controls the engine’s; and thus the propeller’s; speed. Think of the propeller as a spinning vertical wing.
The throttle is simply a fuel feeder. Pushing the throttle in (toward the instrument panel) works just like pressing the accelerator pedal on your car. The only difference is that the aircraft throttle isn’t spring-loaded to return to its original position. On a car you must keep your foot on the pedal. In an airplane you push the throttle shaft in or pull it out and it stays where it stopped.
"Man cannot discover new oceans unless he has the courage to lose sight of the shore."
-- Andre Gide