Our solar system is part of the Milky_Way, which on a clear night can be seen as a hazily luminous band in the sky. It is a spiral galaxy. Beyond the Milky Way, there are thousands of other galaxies of various types. They seem to be located in clusters, which in turn form superclusters or immense galactic systems.
Some galaxies have a powerful source of energy, which shines brightly, at their center. These are quasars, which are normally accompanied by a black hole. A black hole is a region in space where everything disappears because of its extremely strong gravitational pull. Neither light nor other forms of energy can escape from a black hole. Within the Milky Way, there are numerous star clusters, which are divided into open and globular clusters.
