We strongly recommend you take advantage of this feature. Chapters allow you to break the content down visually in the section list (table of contents)
You can see which chapters are defined by opening up the table of contents. You can see that each chapter is bold and sections within each chapter are numbered accordingly.
To define a chapter, you should first select a page in the editor. Next, press the Settings buttons. The Page tab should already be selected.
To set this page as the start of a new chapter, enable the Set section as chapter slider.