bi-modality of galaxy types

Galaxies tend to fall into two main categories: elliptical and spiral. Elliptical galaxies are rounded and featureless, composed mostly of older stars with little new star formation. Spiral galaxies, like our Milky Way, have a flat, disk shape with spiral arms full of young stars, suggesting ongoing star creation. This "bi-modality" reflects differences in their formation and evolution histories, with some galaxies evolving into elliptical types through collisions, while others develop into spiral structures. Essentially, the universe shows a clear preference for these two galaxy designs, highlighting diverse pathways in galaxy development.