A planetary system is a group of celestial objects bound by gravity to one or more stars. These systems typically consist of a central host star, which provides the energy and gravitational anchor, along with a diverse collection of orbiting bodies. These components include planets, which are characterized by being massive enough to achieve hydrostatic equilibrium, and moons, which are natural satellites orbiting planets. Furthermore, the system often contains smaller objects such as asteroids, comets, and dwarf planets. The structure and dynamics of a planetary system are governed by complex principles of orbital mechanics and stellar physics, dictating the radial distribution and chemical makeup of its inhabitants over vast spans of cosmic time.