Where can I see how Yii2 works internally?

Question

Yii

Hi all!
Where can I see how yii2 works inside. To understand the code and try to create your own small framework?

Answer 1

https://github.com/yiisoft/yii2

Answer 2

What for? With approximately the same "success" you can try to figure out exactly how the car's engine works, with all its automation - long, dreary, difficult and incomprehensible what it will give.