A Black Hole is an area of space with a gravitational field so strong that nothing, no particles or even electromagnetic radiation such as light, can escape it. The crushing weight of constituent matter falling in from all sides compresses to a point of zero volume and infinite density called the singularity.
Reference Definition by NASA: A Black Hole is a place in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying.
Related Definitions in the Project: The Science Definitions
