What keeps a plane on the ground?

A plane remains on the ground primarily due to the force of gravity, which pulls it downward, and the friction between its tires and the runway surface. Additionally, the aircraft's weight, which is the result of its mass and the force of gravity, must be overcome by thrust generated by the engines for it to take off. Until the thrust exceeds the drag and the lift generated by the wings is sufficient to counteract gravity, the plane will stay grounded.