Breaks are a feature to show a page content peace for peace and not all at once. It is made by adding {{{BREAK}}} in your data-tag, at best put the breaks as a single line with no other content in it before or after the break statement including whitespace.
At every {{{BREAK}}} the page is splitted into two pages, one containing the content until the break (and an continue link) and one page without this break. So a page with four breaks will create five subpages.