A black hole is believed to be created when a star collapses. When a massive star exhausts its nuclear fuel, it undergoes a gravitational collapse. If the remaining mass is at least three times the mass of our Sun, the gravitational forces overcome all internal pressures, leading to the creation of a singularity—a point of extremely high density and gravitational force from which nothing, not even light, can escape. This phenomenon is what we know as a black hole.