The Harvard classification is a system used to categorize galaxies based on their shapes and structures. Developed by astronomers at Harvard University, it primarily divides galaxies into three main types: elliptical, spiral, and irregular. This classification helps astronomers understand the formation and evolution of galaxies in the universe. In the Harvard classification, elliptical galaxies are smooth and featureless, while spiral galaxies have distinct arms winding around a central bulge. Irregular galaxies lack a defined shape and often result from gravitational interactions. This system provides a framework for studying the diverse characteristics of galaxies and their distribution in the cosmos.