Interstellar space is the vast, seemingly empty region between stars in a galaxy. It is primarily composed of hydrogen and helium gas, along with cosmic dust and radiation. This space is not completely empty; it contains low-density matter and is the medium through which light and cosmic rays travel. Exploring interstellar space is crucial for understanding the universe's structure and evolution. It is the area where stellar winds from stars interact with the interstellar medium, influencing star formation and the dynamics of galaxies. Missions like Voyager 1 have provided valuable data about this mysterious expanse.