In this chapter, we will build a component library that can be used not only in our applications but can also be published on npm so that it can be used by any other applications that want to use our component library. Reusable component libraries are something that make teams build awesome applications super fast. We will be building a drop-down reusable component library that will be so flexible that it can be used multiple times in the application. 

The following topics will be covered in this chapter:

• Understanding Angular CDK
• Creating drop-down functionality
• Adding accessibility support
• Publishing a library on npm
• Introducing Angular elements