Answer : black hole is an area in space where matter (what everything is made of) has collapsed in on itself.
Explaination : A black hole is a region in space where the gravitational pull is so strong that nothing, not even light, can escape from it. They form when massive stars collapse under their own gravity at the end of their life cycles. The gravitational force at the core of the collapsing star becomes so intense that it squeezes matter into a tiny space, creating a singularity with infinite density.
Black holes come in different sizes, from relatively small ones formed by collapsed stars to supermassive black holes found at the centers of galaxies, which can be millions or even billions of times more massive than our Sun. These cosmic objects are fascinating to scientists because they challenge our understanding of physics, particularly in the extreme conditions near the singularity where the laws of general relativity and quantum mechanics collide.