Exoplanetary systems are groups of planets that orbit stars outside our solar system. These systems can vary widely in their composition, size, and distance from their host stars. Some exoplanets are similar to Earth, while others are gas giants like Jupiter or Saturn. Scientists study these systems to understand the diversity of planetary formations and the potential for life beyond our planet. The discovery of exoplanets has been made possible through various methods, including the transit method and radial velocity method. Thousands of exoplanets have been identified, leading to the exploration of their atmospheres and conditions. This research helps astronomers learn more about the universe and the possibilities for habitable worlds.