Saturn formed according to one of two models: the core accretion model, which states that planets formed over time through gravitational forces drawing materials together, or the disk instability model, which states that clumps of dust and gas fused together quickly and progressively formed a planet.
The core accretion model describes the formation of planets like Saturn from a solar nebula, comprised of dust and gas that collapsed through gravity to form the sun. Remaining material fused together. Denser, harder materials formed the rocky planets while hydrogen and helium were swept farther away to form the gas giants, like Saturn. Saturn's composition includes mostly hydrogen with some helium. With Saturn's dense core, the planet's gravity drew more elements into its orbit. During this formation, Saturn could not absorb all the broken material, which subsequently orbited the planet in a ring system. The core accretion model indicates a planet's formation takes several million years.
The disk instability model describes the development of Saturn through the binding of clumps of dust and gas early in its formation. Unlike core accretion, this model happened over a shorter time frame, which allowed Saturn to develop its core rapidly, capture lighter gases quickly and reach a mass stable enough to avoid the sun's own gravitational forces.