One of the most famous moons of Saturn is called Enceladus. Space probes have seen jets of water vapour and ice being thrown out of the surface and into space. Scientists think this is because it has an ocean which covers the planet and is hidden below a thick crust of ice. Another moon, Mimas, might also have water on its surface.
As well as the moons, Saturn also has a series of rings which are made of small rocks, dust and ice. Most of these objects are microscopic, but there are some rocks in the rings which have diameters of hundreds of metres. It is thought that the orbit of Saturn's moons give the rings their shape. Especially the gaps in between them.