If it's small and doesn't cause anybody any trouble, it's a meteor.
Thousands of those fall to Earth every day. Maybe millions.
If it happens at night and you happen to be looking in the sky,
you see a "shooting star".
If it's big enough, it would be called an asteroid. None of those
have fallen to Earth for millions of years. If one did, it would be
a giant headache for everybody on Earth. An asteroid more than
a few miles across could could easily wipe out all life on Earth.
