Galaxies are large collections of stars, interstellar gas, dust, and dark matter in space. They are the basic building blocks of the universe and come in various shapes, sizes and structures.
Galaxies also form groups and clusters that are linked together by gravity. These galactic clusters can range from a few to thousands of galaxies.
Our Universe contains a multitude of galaxies, some of which are billions of light-years from Earth. Exploring and understanding galaxies helps us to better understand the formation, evolution and structure of the Universe.