I watched the first video. It wasn't much better than thee docs; still a little obscure and was just "talk" without any solid examples or use cases. But finally, at around 13:30, they get to say what they mean by "fact". If you want to know if it's something that can be useful to you, you can just skip to this part of video: http://www.youtube.com/watch?v=RKcqYZZ9RDY&feature=playe...