In astronomy, the term for a large system of stars, gas, and dust bound together by gravity is a galaxy. Our home galaxy is the Milky Way, which contains billions of stars, along with various celestial objects such as planets, nebulae, and black holes. Galaxies can vary in shape, size, and structure, often classified as spiral, elliptical, or irregular. The study of galaxies helps astronomers understand the universe’s formation, evolution, and the cosmic web that connects them.