Black holes are some of the most mysterious objects in all of astronomy, but we now have solid observational evidence for not just their existence, but the existence of both “stellar-mass” and “super-massive” black holes. Use specific examples to describe the typical masses, locations, and most common observational evidence for both stellar-mass and super-massive black holes. Describe how black holes detected by the LIGO-Virgo collaboration are different from either of these comparatively well-known types.