1. Mass of the objects: The more massive the objects, the stronger the gravitational force between them. This is why the Earth has a stronger gravitational pull than, say, a bowling ball.
2. Distance between the objects: The closer the objects are to each other, the stronger the gravitational force between them. This is why you feel a stronger pull from the Earth when you are standing on its surface compared to when you are in space.
So, to summarize: More mass and less distance both contribute to a stronger gravitational force.
