This is a mostly empty page, demonstrating the use of SubPages.
By the way, SecondNewPage is distinct from SubPages/SecondNewPage but /SecondNewPage is shorthand for SubPages/SecondNewPage.
Notice that when you make /SecondNewPage here, it is not a subpage of this page, but of the SubPages page. All subpages of a main page are peers. Hierarchy is limited to one level.