One book style that the girls learned is called accordion fold. This is where you fold paper like an accordion and slip the ends together to expand the book. You are able to write, draw on any of the "pages" front and back to tell your story. These are usually a small booklet, for small pictures or short phrases.
The other style is simple Japanese stab binding. This is where you can stack different types of paper; ie textured, colored, different weights of paper; that are stacked on top of each other cut the same size.
The girls learned a lot about what goes into binding different books. It will be interesting to see if they use one of these bindings for a project in school.