If you have seen a bright light streak across the sky, you have likely seen a meteor. Meteors are rocks from space that hit Earth's atmosphere and are commonly referred to as falling stars or shooting stars. They are easier to see at night, and meteor showers can make spectacular light shows.
The term meteor is used when a space rock, often caused by a collision of two asteroids, enters Earth's atmosphere. This differentiates it from a meteoroid, which is a rock that is only in space, and a meteorite, which is a meteor that has made it all the way to the ground.
When a meteor enters Earth's atmosphere, it burns. Most burn away completely before ever reaching the ground. What they are made of can change the color they burn, such as meteors made mostly of iron appearing yellow. Meteors are also classified based on their behavior and size and include earthgrazers, fireballs, bolides, and superbolides.