Our outer space is a dark territory. Unless we are self-illuminating, we become a part of this darkness. We can light a matchstick, a candle, a lantern or a bulb on this earth but in outer space, only the Sun and the Stars who have their own light can light up the universe.
This world, our human race, has been fighting against this darkness since ages and yet, that struggle continues everywhere; be it at an individual level or affecting the large population at a particular time.
There are no types of this darkness, they all merge from everywhere and appear as one, while light you can get all levels of illumination from just a flicker to the sun itself.