A Galaxy Catalog is a comprehensive collection of data that lists and describes various galaxies in the universe. These catalogs typically include information such as the galaxy's name, type, distance from Earth, size, and brightness. Astronomers use these catalogs to study the properties and distribution of galaxies, helping to enhance our understanding of the cosmos. One of the most famous examples of a galaxy catalog is the Messier Catalog, created by the French astronomer Charles Messier in the 18th century. This catalog includes 110 astronomical objects, primarily galaxies, nebulae, and star clusters, and serves as a valuable resource for both professional and amateur astronomers.