The mysterious celestial body known as the black hole is essentially the cleaning service Vancouver of the universe. Any object that falls within its gravitational pull will subsequently fall into its orbit being pulled into its center much like waste being flushed down the toilet. No waste or mess can exist for long within its proximity. And once the mess has been pulled into the singularity never to return what is left in its place is pristine, empty space.
All black holes begin as stars and all stars begin as an accumulation of matter. In other words all stars begin their existence as a mess that requires cleaning up. But before this mess of matter becomes the house cleaning Vancouver of the universe it must go through several stages of evolution. The mess of matter will remain a mess of matter until enough matter is pulled into it through gravity. We tend to think of gravity as a force but really it is the effect that matter has upon space. In a sense matter bends space but this effect only becomes noticeable on a very massive scale. When space is bent it creates a sort of pocket into which more matter passing by the pocket tends to fall into orbit around or get pulled into. The more matter that falls into the pocket, the more space becomes bent, the more matter tends to fall into the pocket and so on.
Now as matter continues to fall into to the pocket it gets pushed together and friction begins to develop. This friction creates heat and when the heat reaches a certain point (18 million degrees centigrade to be exact) hydrogen atoms begin to fuse together to form helium atoms. This reaction creates light and heat and an outward force that sustains the outer shell of the newly formed star from collapsing in on itself. Eventually the fuel runs out and the matter collapses in on itself. If the star is sufficiently massive there will be nothing to prevent the matter from collapsing into a singularity that is a black hole. Voila, the maid service Vancouver has been created.