system
Given the following post, respond as if you're commenting on Reddit:
human
Why are Saturns rings all on the same plane?
gpt
You'll find that the answer to this question is similar to the answers you'll receive for questions like "Why do all the planets orbit in the same plane?" Planetary rings fundamentally follow the same principles and the consequence is that the chunks of the ring orbit the planet in a coplanar fashion, but let's get down to actually why: 

Stars form as a consequence of the contraction of interstellar clouds of gas and dust that collapse under their own gravity and begin to heat at their centers as the pressure in the inner parts of the cloud begin to increase. The material within the plane of rotation (Basically the approximate net rotational direction of the entirety of the cloud, which cannot be zero just from a statistical perspective) will remain distributed around the protostar in the center with enough velocity to maintain stable orbits. 

The cloud shrinks, angular momentum must be conserved, and so you end up with an increased angular velocity that allows them to stay in that plane of rotation, moving fast enough not to fall into the star. The remainder of this material, that above and below this plane, freely collapse inward as there's no force preventing them from continuing to fall into the center of the protostellar nebula. 

When the planets began to form, they did pretty much the same thing, but on smaller, obviously planetary scales. Rocky material would accrete into bodies orbiting the star with the same direction, and the material would come to rotate in the same direction as the cloud was rotating, which makes sense because the material would always have that initial velocity in that direction and it would simply compound to induce a rotation in that same direction. As a result of this, the various moons that orbit Saturn would come to orbit it in the same rotational orientation. 

There isn't a conclusive explanation to where exactly Saturn's rings came from, but the two prevailing theories are that they are either debris from a moon whose orbit decayed to below the Roche limit and was disintegrated by tidal forces, or they are simply leftover material from the formation of the planet billions of years ago. Either way, they still would ultimately orbit the planet in a single plane of rotation- Everything else fell into the center of gravity to ultimately make Saturn, material orbiting within the rotational plane moving quick enough maintained stable orbits and so we see that the moons and rings of Saturn exist in a roughly coplanar orientation.