If I understand it correctly it has to do with the universe really being a two-dimensional surface full of all the information that makes up our reality. This information is then projected or just perceived as three dimensions. This idea is born from the theory that the matter and energy lost is a black hole is copied to its surface. Possibly meaning our universe is the interior of a black hole and all of the black holes in our universe are universes as well. I'm not a physicist but from what I've read this is how I understand it.