Falling star is a term used to describe two celestial phenomena: meteors and comets. Meteors, also known as shooting stars, are small pieces of rock or dust that enter Earth's atmosphere and burn up, creating a bright streak of light in the night sky. Comets, on the other hand, are icy bodies that orbit the sun and can be seen from Earth as they pass by. Both meteors and comets are often referred to as falling stars due to their appearance in the night sky.