What are Lagrange points?

The answer

Lagrange points are five positions in a two-body orbital system (like Earth-Sun) where the gravitational forces and centrifugal force balance perfectly, allowing a small object to remain in a stable position relative to both bodies. L1 and L2 are particularly useful for space telescopes - the James Webb Space Telescope orbits the Sun-Earth L2 point, 1.5 million km from Earth, where it maintains a constant position relative to both the Earth and Sun. L4 and L5 are the most stable, which is why Jupiter's L4 and L5 points have accumulated thousands of Trojan asteroids.