Gravity is a fundamental force that attracts two bodies towards each other. It is responsible for keeping planets in orbit around stars, moons around planets, and objects on the ground. The strength of gravity depends on the mass of the objects and the distance between them, as described by Isaac Newton's law of universal gravitation. In modern physics, gravity is explained by Albert Einstein's theory of general relativity, which describes it as the curvature of space-time caused by mass. This means that massive objects like Earth warp the space around them, influencing the motion of other objects nearby.