A planetary system consists of the non-stellar objects orbiting a star. Of current observational interest are planets and circumstellar disks, but systems are also presumed to have bodies too small to be observed given their distance, given the example of the solar system. The term planet multiplicity refers to the number of planets, e.g., eight for the solar system.
The term star system has a similar meaning, but includes the star (or binary star). A planetary system may involve planets orbiting more than one star, e.g., circumbinary planets.