It’s basically impossible to give a short, succinct description of black holes that is also in any way even vaguely correct. They are so completely different from anything we encounter in daily life that even metaphors fail.
So the best way to think of it, for the layperson just going about life wanting to be essentially educated as to how the universe works, is to imagine a very large, very old star. This star has used up all its fusion “fuel,” if you will, and will soon collapse, exploding spectacularly in an apocalyptic cataclysm of radiation that will, briefly, outshine its whole galaxy.
