Black holes are objects that have gravitational fields so strong that nothing, not even light, can escape from them. They are often found at the center of galaxies and are the most massive objects in space. The term "black hole" was coined by physicist John Wheeler in 1967.
Black holes come in many different shapes and sizes. They range in size from small black holes with the mass of a car to supermassive black holes with the mass of millions of suns.
In astronomy, they are often called "stellar mass black holes" or "primordial black holes."
A stellar mass black hole forms when a star dies and collapses under its own weight. It is typically the size of the Earth, but can grow to be as large as 20 times the size of our sun.
The primordial black holes are believed to be the seeds of all the galaxies in the universe. They were formed when the universe was only a few hundred million years old and started with a tiny size.