Galaxies consist of stars, planets, and vast clouds of gas and dust, all bound together by gravity. The largest contain trillions of stars and can be more than a million light-years across. The smallest can contain a few thousand stars and span just a few hundred light-years. A galaxy is a system of stars, stellar remnants, interstellar gas, dust, and dark matter bound together by gravity. [1][2] The word is derived from the Greek galaxias (γαλαξίας), meaning 'milky', a reference to the Milky Way galaxy that contains the Solar System. What is a galaxy? A galaxy is any of the systems of stars and interstellar matter that make up the universe. Many such assemblages are so enormous that they contain hundreds of billions of stars. Galaxies usually exist in clusters, some of which measure hundreds of millions of light-years across. Discover our newest Galaxy smartphones and explore Samsung's full lineup—including the Galaxy S25 Series, Flip and Fold phones, Fan Edition, A Series 5G, and more. For more than 15 years Galaxy Zoo volunteers have helped astronomers make sense of the beautiful complexity of galaxies in our Universe. We appreciate each and every one of your classifications. Look at telescope images of distant galaxies. Explore the sky. What will you find? What is a Galaxy? A galaxy is a system of stars, stellar remnants, interstellar gas, dust, and dark matter bound together by gravitational forces. A galaxy can contain hundreds of billions of stars and be many thousands of light-years across. Our own galaxy, the Milky Way, is around 100,000 light-years in diameter. An independent bookstore specializing in sci-fi, fantasy, horror, mystery, and romance. Galaxy Theatres, LLC is a fully integrated movie theatre company. Privately owned, it is ranked by size in the top 10% of its industry, according to the National Association of Theatre Owners and currently has theatres in Arizona, California, Nevada, Texas, and Washington. Galaxy is a community-driven web-based analysis platform for life science research.