The three types of galaxies are:
1. Spiral galaxies: These galaxies have a distinct spiral structure, with arms extending from a central bulge. They usually have a disk shape with a flat, rotating disk of stars, gas, and dust. Examples include the Milky Way, Andromeda Galaxy, and Whirlpool Galaxy.
2. Elliptical galaxies: These galaxies have a more rounded shape, resembling a three-dimensional ellipse. They lack the prominent arms and disk structure seen in spiral galaxies. Elliptical galaxies vary in size and can range from small to massive. Examples include M87 and the Sombrero Galaxy.
3. Irregular galaxies: These galaxies do not have a well-defined shape and do not fit into the categories of either spiral or elliptical galaxies. They often appear more chaotic and disorganized, with irregular distribution of stars, gas, and dust. Examples include the Large and Small Magellanic Clouds.