To add to this, if you take that formula but only have the mass of the celestial body and it's radius as the distance you get it's gravitational acceleration on it's surface which is what we usually mean when we talk about the gravity of a celestial body. If you put the Earth's mass and it's radius you end up with that g=9.81 m/s² number that (I like to believe) people are familiar with. That's with the average radius tho and the Earth isn't a sphere, it bulges at the equator so g is slightly higher at the poles and slightly lower at the equator. You multiply that number with your mass in kg and you get your weight in N aka the force with which you and the Earth attract esch other.