These guides are resources for the developers who are working on the Cardstack codebase itself.
If you are building projects and cards that are powered by Cardstack, you don't need to know this information. However, you might find it interesting to learn how things work under the hood!
The main Cardstack codebase can be found on GitHub.
From an outside perspective it is clear that a lot of the underlying concepts in Cardstack reflect some of the useful architectural decisions of Ember. If you are familiar with Ember then you are likely going to understand the most/all of these concepts without too much effort.