What are the four names of the galaxies?

The four primary types of galaxies are spiral galaxies, elliptical galaxies, lenticular galaxies, and irregular galaxies. Spiral galaxies, like the Milky Way, have a distinct spiral structure, while elliptical galaxies are more rounded and smooth. Lenticular galaxies are a hybrid form with features of both spiral and elliptical galaxies, and irregular galaxies lack a defined shape. Each type showcases unique characteristics and formation processes in the universe.