Breaks can be a powerful thing in Flare, if used correctly. When producing printed output, Flare needs to know where a new chapter will start. Besides that: if you have created different page layouts for different topics in your document you want to use them.
A lot of writers would just implement page and/or chapter breaks in the topic itself. But that is definitely the wrong thing to do. Instead: indicate that a new chapter will start by setting chapter breaks at the apt location in your (manually created) TOC.
To add chapter breaks in your document:
You can also select Page Layout break in the Break Type box.
By default, Flare will keep the same page layout for every topic, except if you choose a specific one as mentioned in the step above.