According to Mastering Astronomy, Jupiter is bigger because it's mass is compressed more, thus increasing its density.
Saturn's lower density compared to Jupiter is the main reason why it is almost as big despite having a smaller mass. This lower density results in Saturn's gases being spread out over a larger volume, giving it a similar size to Jupiter.
It's smaller. The Sun is almost 10 times the size of Jupiter, and it's not considered a large star.
The biggest planet in our solar system that has rings is Jupiter. If the diameters of the rings are being compared, Jupiter's rings have the largest diameter in our solar system, at almost twice that of Saturn's.
What foolishness! Even Jupiter is much smaller than our great star! Then, why Saturn? These are the areas of the Solar System of Sun and Planets Sun 22,40,84,390 Jupiter 1,75,95,000 Saturn 99,65,000 Uranus 65,00,000 Neptune 64,24,700 Earth 58,10,200 Venus 52,08,196 Mars 40,00,000 Mercury 32,05,370 It means that 99.8% of our Solar System includes Sun, and only the remaining 0.2% constitute the planets. In that mass, 92% are in the gas giants. Neptune is almost thrice of four times larger than Earth, but in many pictures, it it drawn larger than it's actual size. The areas of gas giants are measured without their rings. If you take their rings, they will become even larger, no doubt.
Saturn rotates once every 10.5 Earth hours. FAST !! That's why it's center bulges out a little... same with Jupiter. Jupiter rotates about every 9 hours. BUT - it takes almost 30 Earth years to make one revolution around the sun.
Saturn's lower density compared to Jupiter is the main reason why it is almost as big despite having a smaller mass. This lower density results in Saturn's gases being spread out over a larger volume, giving it a similar size to Jupiter.
Based on the quantity of 9 total (include Pluto), -- 3 are smaller, (Mercury, Mars, Pluto), -- 1 is almost identical, just a bit smaller, (Venus), -- 4 are larger (Jupiter, Saturn, Uranus, Neptune).
Neptune, Uranus, Saturn and Jupiter are never seen as crescents from Earth. They are always "almost full".
It's smaller. The Sun is almost 10 times the size of Jupiter, and it's not considered a large star.
Neptune is very similar to Uranus in size. Its diameter is only slightly smaller, at 49,528 km across. It is almost as big as four Earths in a row. I'm not sure about the number though - I think its 3rd or 4th after Jupiter and Saturn
Jupiter and Saturn, though there is Helium and Hydrogen on Neptune and Uranus. The two buish planets are mostly menthane, which makes them blue. But Jupiter and Saturn have the most helium and hydrogen.
Strictly speaking, none. Mercury and Venus have none. Earth, one. Mars, two. Jupiter, Saturn, Uranus and Neptune have more than four. Jupiter has 63 known moons, Saturn has at least 60. Uranus has 27, and Neptune 13. The vast majority of these moons are puny - 300 km across and smaller. Saturn only has 1 large moon, Titan, which is also the only known moon with a substantial atmosphere. Jupiter has 4 large moons (and perhaps this is the source of your question). These range from Ganymede (larger than Mercury), Callisto (almost as big), Io (a little bigger than our Moon), and Europa (a little smaller than our moon). After our Moon, nothing else in our solar system even compares.
Mars is potentially the closest planet at a minimum distance of 3.68 AU. That varies. Mars would typically be the closest planet, but earth would be closest when earth and Jupiter are on the same side of the sun and Mars is on the opposite side. At 10 AU, Saturn would almost always be further from Jupiter than Mercury or Venus. When Mars and Jupiter are on opposite sides of the sun, the distance between them is eight AU, whereas the distance between Jupiter and Saturn when they are lined up on the same side of the sun is 5 AU. That means when even earth (1 AU) is on the opposite side from Jupiter and Saturn (Jupiter and Saturn are in daylight), Saturn would be slightly closer. Most of the time, however, Mars would be the closest planet to Jupiter.
The biggest planet in our solar system that has rings is Jupiter. If the diameters of the rings are being compared, Jupiter's rings have the largest diameter in our solar system, at almost twice that of Saturn's.
The largest gas giant in our solar system with multiple moons is Jupiter. Saturn is second, with almost as many moons (around 60), followed by Uranus and Neptune.
Jupiter has 63 known natural satellites (with a 64th and more possible as of 2008). Saturn has 60 or more, Uranus 27 or more, Neptune 13 currently known, and Pluto has three confirmed moons (the largest, Charon, is nearly the same size as Pluto).
Jupiter's magnetic field is the largest in the solar system, extending over 7 million kilometers in the direction of the Sun and almost to the orbit of Saturn in the opposite direction. This magnetic field is about 14 times stronger than Earth's.