Wow, congratulations on making it through this chapter! It was a long and tough road, but you persevered. While the main focus of this chapter was HoloLens input and Gaze, Gesture, and Voice, or GGV, we needed to learn a few other things first so that we could see the input happen.
We discussed Prefabs and object templates, which allow us to instantiate and save memory in the process. An important, but not terribly tough concept--parentage--was then covered, because Prefabs are often just a collection of various children.
We took a look at how to use a simple keyframe animation to move an object around. We also learned how to write a basic script so that we can airtap our object to make it animate.
Next, we covered Materials, Textures, ...