Friday the 13th

So there's a remake of Friday the 13th coming out in February. I think it looks good and I'm definitely seeing it, but there's something about it that I don't quite understand. In the first film, Jason wasn't the killer! But as you can see, he IS in this new one. And then in the second film, Jason doesn't even have the hockey mask! I'm really interested in how everything's put together in this new Friday the 13th. Is it the same story as in the first film, but with Jason as the killer instead of his mom? Is his mom a big part of the story? I read in this set visit report that Jason's mom is seen in flashback sequences. Hmmmm. I understand that it's not only a remake, but also more of a re-imagining of the film, which makes me even more interested. I can't wait to find out the answers to my questions.