Lagrange points are specific locations in space where the gravitational forces of two large bodies, like Earth and the Moon, balance with the centrifugal force felt by a smaller object. This allows the smaller object to maintain a stable position relative to the two larger bodies. There are five such points, labeled L1 through L5. The most commonly used Lagrange points are L1, L2, and L3, which lie along the line connecting the two large bodies. L4 and L5 form an equilateral triangle with them. These points are useful for placing satellites and space observatories, as they require minimal energy to maintain their position.