Prezi Next uses smart structures to organize presentations. The Prezi Layout is how the presentation is structured. It is a suggestion on how to distribute the elements on each of your topics. If you follow these suggestions, you will end with a presentation that looks the same and has a consistent style and theme throughout the presentation.
So remember, we can not use the layout in the overview, but once we go into a topic, we can choose a specific layout.
Remember
Shapes are the specific form of your topics and subtopic, such as circles, squares, etc. While choosing the layout, you are talking about the structure of the presentation.
There is an advanced lesson on Prezi Shapes, in which you will learn how to edit shapes.