Gravity keeps the Sun, earth and moon in position.
Gravity causes a pull on objects
More mass causes a greatergravitationalpull, The more mass an object has the more masses it attracts..
Gravity is the pull of two or more objects on eachother.
EVERY OBJECT EXERTS GRAVITATIONAL PULL BUT IT IS PROPORTIONAL TO THE MASS OF THE OBJECT.
The mass of an object stays the same wherever it is
But its weight can change, weight is determined by gravitational force.
The earth pulls on you and you pull the earth its just that earth is so big that its gravitational force pulls you to it. and you dont pull it because you are small