It's well known that there are Lazy Loading approach and Eager Loading approach in the relational query. But it's very important to know how the Eager Loading approach works in Yii 2. It has changed drastically from that of Yii 1.1, and there are common misunderstandings about it in the community.
This is a central location to collect links to "Getting Started" documentation beyond the blog demo and Creating First Yii Application. Please help the community by adding general, introductory links and descriptions to this page.