In space, there are lots of particles and bits of rock floating around.
Every now and then, one of these tiny pieces of rock enters the top of the earth’s atmosphere. Because it is travelling so quickly it appears to burn up in the upper atmosphere and that is what we see as a shooting star.
Shooting stars are not actually stars, just a piece of debris or rock that’s coming into our atmosphere.
Most shooting stars come from pieces of rock that are from the size of a grain of sand (which is really tiny) up to probably about a meter in diameter.
As they are not actually that big, it is quite impressive that we can see them all the way from the ground and they can streak right across the sky!