Light is a form of electromagnetic radiation that travels in waves or particles called photons. It comes from the sun and stars, where electrons in atoms get excited and jump to higher orbits. When they fall back down, they emit photons of light. The color of light depends on the energy level of the electron jump. Light can act as both a particle and a wave, traveling at 300 million meters per second. When light interacts with matter, it can be transmitted, reflected, absorbed, or scattered depending on the object. Astronomers study light from stars to learn about their composition, temperature, and movement.