|Saturn's core is composed liquid rock. This core is surrounded by a layer of liquid hydrogen. It is under such high pressure that the nature of the hydrogen changes, and is able to conduct electricity like metal. This generates the planet's magnetic field.
The layer on top of this is ordinary liquid hydrogen. Next, the hydrogen thins out into the gaseous atmosphere. It is composed of mainly hydrogen and helium with trace amounts of methane, water, ammonia, and hydrogen sulfide.