Gravitational force
Also called Force of gravity, Gravity
The gravitational force is the mutual attraction between any two objects with mass, acting along the line joining their centers of mass. Near an astronomical body AP gives the same force a second name, weight.
One interaction, three pieces of AP vocabulary, and telling them apart is most of the work.
The force. AP Physics 1 EK 2.6.A.1 describes it as directly proportional to each of the two masses and inversely proportional to the square of the distance between the systems' centers of mass. It is attractive (EK 2.6.A.1.i), always exerted along the line connecting the two centers of mass (EK 2.6.A.1.ii), and treatable as acting at a system's center of mass (EK 2.6.A.1.iii), which is why a free body diagram carries one weight arrow from one point.
The name near a planet. EK 2.6.A.3: the gravitational force exerted by an astronomical body on a relatively small nearby object is called weight.
The force per unit mass. That ratio is the gravitational field, a property of the point in space rather than of whatever sits there.
Why everything falls at the same rate. The CED separates two meanings of mass and then joins them. EK 2.6.D.1 calls inertial mass the property determining how much an object's motion resists changes, EK 2.6.D.2 makes gravitational mass the one related to the force of attraction, and EK 2.6.D.3 states that the two have been experimentally verified to be equivalent. The mass being pulled is the mass that resists, so it cancels out of Newton's second law and a feather and an anvil accelerate alike in a vacuum.
Both objects feel the same size of force in opposite directions, however lopsided the masses; only the accelerations differ. The equation and its inverse square behaviour sit at Newton's law of universal gravitation.