What Is a Black Hole

A black hole is a region in spacetime where the gravitational pull is so strong that nothing, including light, can escape. Black holes have been observed in various forms, including stellar-mass black holes and supermassive black holes. The observation of black holes has been made possible by advanced technologies such as the Hubble Space Telescope and the Event Horizon Telescope. The concept of black holes has evolved over time, from initial considerations in the 18th century to the present day.