This website explains the force of. Gravity is the force that makes two objects pull towards each other. We are pulled toward the center of the Earth because of the gravitational pull caused by its mass. The more mass the object have, the more gravity it will have. This is why heavier people are pulled harder to the ground. Planets orbit around huge stars because the stars have more mass and gravity. An example is the Earth orbiting around the sun. The Earth stays in the “track” that goes around the sun because of the gravitational pull the sun has towards it’s middle. This website is a good source for learning about gravity and how it works.