A black hole is a body in space which does not allow any radiation to conic out. This property is due to its

A black hole is a region of spacetime where gravity is so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it.

The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole.

The boundary of no escape is called the event horizon.

Although it has an enormous effect on the fate and circumstances of an object crossing it, according to general relativity it has no locally detectable features.

In many ways, a black hole acts like an ideal black body, as it reflects no light.