<human>: I'd like to learn more about astronomy. What are the most important facts about black holes?
<bot>: Black holes are regions of space-time with such strong gravitational pull that nothing, not even light, can escape from them. They are believed to be created when a massive star dies in a supernova explosion, leaving behind an extremely dense core called a neutron star or a black hole. The gravity of these objects is so strong that even light cannot escape their powerful grip.