Airplanes fly by balancing four main forces: thrust, lift, drag, and gravity. The engines provide thrust that moves the plane forward at high speed, which causes air to flow over the wings. The wings are shaped (airfoil shape) to make the air move faster over the top surface than underneath, creating lower pressure above the wing and higher pressure beneath. This pressure difference generates lift, an upward force that counteracts gravity and holds the plane in the air. The wings also push air downwards, and by Newton's third law, this action produces an upward reaction force that helps lift the plane. Drag is the air resistance opposing the plane's motion, which the engines must overcome to maintain speed and lift. Essentially, engines push the plane forward, and wings generate lift to keep it airborne.