In this chapter, we learned how to create Polymer and Stencil components. We looked into how these components can be nested to form more complex elements. We also looked into how attributes and properties can be passed into child components in both Polymer and Stencil components. 

We also looked into the pre-rendering feature of Stencil, and how it can be used to make a site perform better. 

In the next chapter, we will look into how vanilla Web Components can be used in various other libraries and frameworks.