That's a lot of framework theory and understanding you have gone through here and we still haven't actually built any real UI. Fear not, as from here we start building with a vengeance.
The previous concepts are really important to understand going forward as they are the foundations of the new Unity UI system.
In this chapter, we covered the following topics:
The new Rect Transform system
Many ways to layout your controls
Knowing how to proportion your canvas for multiple resolutions
An overview of the new Event system and its involvement in Unity UI
So we have a canvas and the ability to put stuff in it, so let's rock on with the next chapter and throw some paint on that canvas.