These preview pages are shown to you before every stage of a project.
Here you can see a description of a stage and examples of how it should work (output/input-wise). It helps to see what sort of theoretical and practical knowledge you will acquire during this stage and put things in perspective.
Topics to learn section is visible only if you have more than 8 unlearned topics at this Project Stage.
Here you can choose topics that you already know so that you can skip them.