Plain English Meaning

Stability is how well the airplane holds its own flight path on its own. Controllability is how well it responds when you move the controls. How the airplane is loaded affects both.

Full Definition

Two related but distinct flight characteristics of an aircraft. Stability is the aircraft's tendency to return to its original flight condition after being disturbed (by a gust, control input, or change in power) without pilot effort. Controllability is the aircraft's responsiveness to pilot inputs, allowing the pilot to maneuver it as intended. Both are directly affected by weight and balance: loading outside limits — especially (CG) outside the forward or aft limit — degrades one or both, sometimes severely.