Stars, interstellar gases and dust, plasma, and enormous amounts of unseen matter make up the galaxy, which is a supermassive system of gravitational forces. A typical galaxy has between 10 million and one trillion stars all revolving around a common center of gravity. Galaxies are made up of several cells in addition to single stars. There are clusters and several sorts of nebula in them. The majority of galaxies are a few hundred to a few thousand light-years in size, with distances between galaxies in the millions of light-years.