Final answer:
Planets have different sizes and can have moons, some of which can be as large as smaller planets. All four giant planets also have rings made up of small particles or moonlets.
Step-by-step explanation:
Planets have several characteristics. They can vary in size, ranging from large planets like Jupiter and Saturn to smaller ones like Mercury and Mars. Planets are often accompanied by moons that orbit around them. Some moons can be as large as smaller planets, such as the Galilean moons of Jupiter or Titan and Triton of Saturn and Neptune respectively.
Additionally, all four giant planets in our solar system have rings made up of countless small particles or moonlets that orbit close to them. Each ring system displays a complicated structure that is related to interactions between the ring particles and the larger moons.