This was an intense chapter, but it will provide a solid foundation as you learn how to use RxJava to tackle real-world work. RxJava, with all of its expressive power, has some nuances that are entirely due to the change of mindset it demands. It has done an impressive amount of work taking an imperative language like Java and adapting it to become reactive and functional. But this interoperability requires some understanding of the implementations between an Observable and a Observer. We touched on various ways to create Observables as well as how they interact with Observers.

Take your time trying to digest all this information but do not let it stop you from moving on to the next two chapters, where the usefulness of RxJava starts to take formation. In the next chapters, the pragmatic usefulness of RxJava will start to become clear.