Starting in 2017 Apple products will ship with a new file system: APFS. It will be available on every device that Apple offers. If you're the 'geeky' type and would like to learn more about APFS, here is a video that you can watch (note that it will only run on the Safari browser), and here is an article that explains, in more understandable terms, what the video shows. Realistically, unless you're a developer of apps for an Apple device, you probably won't care about this new file system. But, if you're somewhat 'geeky', and would like to lift the kimono a bit to take a peek at what Apple is up to in their new file system, the video and article will give you a good overview -- that's assuming, of course, that you're able to stay awake.