Why the planet Saturn and has a floating?

You need to clarify. What is a 'floating'?

I mean the rings :]
And it FLOATS!

The exact source of the rings isn't known. Some has accumulated due to Saturn's gravity attracting "loose bits" from collisions destroying moons, asteroids, etc. Check out NASA.gov

When I suggested NASA.gov, I should have specified to check the section on the Cassini spacecraft...

Saturn isn't floating, its orbiting the Sun just like all the other planets. The rings are simply a collection of ice, rock and other particles and larger objects that were captured by Saturn's gravity and stay in obrit around the planet. Here is a site that goes into great detail about the rings of Saturn:

The Alphabet Soup of Saturn's Rings - Explore the Cosmos | The Planetary Society


We are learning that such rings around planets are more common than was previuosly believed, but are not as visible as the rings of Saturn.

Wasn't it Uranus that Voyager found has a ring system?

In addition to Saturn, rings have been discovered around Uranus, Neptune and Jupiter.

The rings around Uranus were discovered in the mid 1970's by a team from Cornell. They were studying the occultation of a star by the planet, as a way of measuring properties of Uranus's atmosphere - by seeing how the light from the star dimmed as the planet moved in front of it they were hoping to determine properties such as the planet's atmospheric density and chemical makeup. They were totally surprised to see that as the planet moved across the star the star light dimmed as the planet moved close, then brightened, then dimmed and went out as the star was occulted. Then when the star emerged from the other side the same pattern repeated, in reverse order. This made it clear that something was circling Uranus that dimmed the star light, and the rings were it. Up until that time everyone thought the Saturnian rings were a complete anomaly whose origin must have required some unique explanations. But as JimG notes, rings have been discovered around all four of the gas giants, so theories about how rings form must take into account that rings are common occurrences.