In this chapter, we learned about Observables and Observers and how to use them. We worked with several examples to get our grips strong on them. We learned that there are two categories of Observables—Hot Observables and Cold Observables. We also learned about several Subject and its variant. Several Subject are basically a combination of Observables and many Observer.

While Observables provide us with great flexibilities and power, it too has some disadvantages, such as backpressure. Curious about it? Want to know more about the disadvantages of Observables and how to overcome them? Rush to the fourth chapter then.