What is a black hole?

Interesting fact:

In layman’s terms, a black hole is an object so massive that nothing can escape its gravitational pull – not even light! Anything can become a black hole if you crunch it to a miniscule size – if we squeezed you to a point smaller than a subatomic particle, you’d become one, too! But in nature, they’re usually formed when massive stars collapse under their own weight at the end of their lives.