Gravity is the attraction between objects that have mass. The more mass, the stronger the pull. Earth pulls you down so you do not float away. The Sun, being vastly more massive, pulls on every planet. Gravity works across empty space. You cannot see it, but it shapes the whole solar system. Without gravity, planets would fly off in straight lines and the Sun would not hold its family of worlds together.
🍎 MASS
Isaac Newton showed that gravity depends on mass and distance. Big objects pull harder.