The asteroid belt was so named because many asteroids are or pass through that sap.
Most asteroids pass or are between Mars and Jupiter, so the asteroid belt has formed.
Those asteroids revolve around the Sun like planets, only they revolve between 3.5 and 6 years, make a complete rotation.
Other celestial bodies were discovered in the asteroid belt, but nothing very special.
We only know that some of those asteroids also visited Earth.
And as far as we know, most asteroids in the Solar System would be there.