A black hole is an area in space with an incredibly strong gravity. This gravity pulls in everything that gets close and nothing can escape from a black hole. Black holes have great amounts of material packed in very tightly. That’s why they are remarkably heavy for their size. They are called “black” because they are invisible. Because no one can see black holes, they are hard to find.
A black hole can be formed when a huge star uses up its fuel. The gravity crushes the star smaller and smaller, and it becomes a black hole. Scientists believe that a huge black hole lies at the center of nearly every galaxy.
The German astronomer Karl Schwarzschild predicted the existence of collapsed stellar bodies that would not emit any radiation. Such cosmic bodies were named black holes about 50 years later.