Extrasolar planets, also known as exoplanets, are planets that orbit stars outside of our solar system. Since the discovery of the first confirmed exoplanet in 1992, thousands of extrasolar planets have been identified using various methods such as the transit method, radial velocity method, and direct imaging. Studying extrasolar planets is important for understanding the diversity of planetary systems in the universe and for expanding our knowledge of planetary formation and evolution. Scientists are particularly interested in identifying Earth-like exoplanets within the habitable zone of their host stars, where conditions may be conducive to the existence of liquid water and potentially life. Research on extrasolar planets involves characterizing their physical properties such as size, mass, atmosphere, and composition, as well as studying their orbital dynamics and potential habitability. Scientists use a range of telescopes and instruments, both ground-based and space-based, to observe and study these distant worlds.