If you like to write in scenes, you can place a scene break at any point in your book and Atticus will automatically break the chapter into scenes for you. You'll be able to see a little drop down arrow beside your chapter title, showing each scene.
You can either work with the chapter as a whole, by clicking on the main title in the left navigation panel, or you can work on each scene individually by clicking on the scene number itself.
Scenes are completely dynamic and will update the main chapter automatically, and you can even drag and drop them into a different order or even a different chapter!
The scene numbers are for your reference only, and will not show in the book.