Home improvement novice here:

Our bathroom had wallpaper in it when we moved into our house, but shortly after it started falling off on it's own (this was several years ago). Underneath was what you see in the attached pictures. I was wondering what exactly it might be and how to repair or possibly replace it. It's cracking in several areas but hasn't started deteriorating, with the exception of the one spot over the bathtub as seen in the pick. There's another spot in my house that I posted a picture of several years ago and was told it was green board. Could this be the same thing? The texture and the way it cracks and flakes makes me think it isn't the same.

Thanks in advance for any assistance you all can provide.