The rings are the 'dust' particles (not really dust because the particles are of very huge in size).
As i saw in NGC, the rings are formed from one of the Moon(satellite) of the Saturn getting exploded due to its gravitational pull and these particles revolve around the planet.
The thickness of the ring doesn't exceed beyond 1KM and each particles travel with different velocity. Hence these collide with themselves, creating smaller particles.
But some of the broken pieces are pushed away to the universe and they cant come back .
One interesting fact is that.... When you go near (like at a distance of Moon to Earth) you will hear a constant sound.
This is what i understood about Saturn from NGC.
Saturn's Rings are jus' amazin' no words.. Jus' like a lovely neckalace in the neck of a beautiful girl.