I first came across this concept in a Scientific American magazine. At the time it was nigh impossible to find much more information on it. Even now I am having a hard time wrapping my head around it. So I have a few questions. From what I understand, it basically says: Every single bit of information in any volume of space can be encoded / written on its surface. Scenario #1: A volume of space, say a cube, could be completely described on its surface, which is 6 flat sides. Scenario #2: A book takes up a volume of space. So everything written in a book could be described on the surface of the book, which again, is 6 sided. Scenario #3: In any given room, everything in that room can be described on the walls of that room. Moving on... Usually when they talk about it, they talk about the universe as a whole or black holes. But it was stated that this idea applies to all space. If it applies to all space, that means it applies to any volume of space you choose, be it a volume of space that contains a book, room, planet or galaxy.