Exoplanetary systems, also known as extrasolar planetary systems, refer to systems of planets orbiting stars outside of our own solar system. The study of exoplanetary systems involves the discovery, characterization, and understanding of these planetary systems, which can provide valuable insights into the formation and evolution of planets and their host stars. Scientists use various techniques, such as the transit method, radial velocity method, and direct imaging, to detect and study exoplanetary systems. The field of exoplanetary systems is rapidly evolving, with new discoveries being made regularly that challenge our understanding of planetary formation and the prevalence of habitable environments in the universe.