Sorry but I can’t find a specific description of the difference between a folder and a page. My intiution is that a folder cannot display the contents such as a list of contents and is hidden, and that a page can (namely, has content that can be displayed). Both can have child pages/folders. Is that the main difference?
To be honest I don’t see the advantage to folders, unless one wants to hide parents, in which case breadcrumbs would break.