Types Of Galaxies C lassified Based On Their Morphological Characteristics. There are several types of galaxies that have been classified based on their morphological characteristics, such as shape, size, and structure. Some of the most common types of galaxies include Spiral galaxies: These galaxies have a distinctive spiral arm pattern, a central bulge, and a flat disk. The spiral arms are regions of active star formation and are thought to be driven by the gravitational potential of the central bulge and disk. Examples of spiral galaxies include the Milky Way and the Andromeda Galaxy. The mass of spiral galaxies can vary widely, with some spiral galaxies having masses of a few billion solar masses, while others have masses in excess of one trillion solar masses. The exact mass of a spiral galaxy depends on various factors, including its size, structure, and the amount of dark matter it contains. As for the diameter, spiral galaxies can be quite large, with some having diameter