Saturn's rings are solid, continuous structures.

Through early telescopes, Saturn’s rings looked like smooth, continuous bands. A solid disk or set of rigid rings was therefore a natural interpretation.

The dynamics created trouble. A rigid ring large enough to encircle Saturn would be difficult to keep stable, and observed gaps and translucent regions suggested that the structure was not a single solid object.

James Clerk Maxwell attacked the problem mathematically in the 1850s. He showed that neither a rigid solid ring nor a continuous fluid ring could remain stable in the required form. The viable solution was a ring made of many separate bodies orbiting Saturn.

In 1895, James Keeler supplied direct observational support through spectroscopy. The inner ring material moved faster than the outer material, exactly as expected for independently orbiting particles following Keplerian motion.

Modern spacecraft have revealed an enormous population of mostly icy particles ranging from dust grains to large blocks and embedded moonlets.

The particles still collide, clump, and interact gravitationally, so the rings can develop waves and collective disk-like structures. They are particulate, not one solid sheet.