Actually, both of the facts are true. The confusion comes because the "real" world and the "computer" world have different mathematical computations. It can get confusing, and for the most part, what you really need to know is when you see the 4.7 on your DVD MEDIA, it is referring to 4.7 billion bytes. Which equates to approximately 4.37 GB's. To simplify, you will need to keep your project to 4.37 GB's or less.