The Magellanic Clouds, two irregular galaxies, are much closer to the Milky Way. Their distance is 50 kpc. 10 million L sun , about 1000 times less luminous than the Milky Way. There are many more faint galaxies than bright galaxies. However, most stars are in galaxies that are roughly as luminous as the Milky Way.
Most galaxies reside in groups.
The typical size is about 1000 kpc. These motions provide more evidence for dark matter. Groups and clusters are themselves arranged in enormous sheets and filaments, called superclusters. Most galaxies live in groups or clusters.