Comparing planets is one way we work to understand them better. Jupiter and Saturn are both large planets that can be seen with binoculars. They are both bright, but we see Jupiter better because it is closer to us.
Jupiter is much larger than Saturn, nearly twice its size. Because they are large planets, they have a lot of gravitation pull, pulling rocks into orbit around them. This gives them each many moons. Some of their moons are as least as large as Mercury.
Jupiter and Saturn have the same types of gases in their atmospheres, but Jupiter is much warmer because it is so much closer to the sun.
Jupiter and Saturn both have rings around them. Uranus and Neptune do as well.