black holes were once really big stars(like really big) that became unstable and werent able to hold up to their own gravitational pull so they emploded and all that matter now being condensed into a tiny little area(like really tiny) created a huge pull on itself. U know how the pull on the earth is like 10m/s, well in a black hole the gravitational pull is greater than the speed of light. So since nothing can travel faster than the speed of light, once somethings in its event horizon(the point of no return) it cant get out, not even light. Thats why its a black hole, u cant see them cuz they give off no light.
I ski at the crappiest hill ever...