All these APIs serve the same purpose, that is, to provide asynchronous Observable streams in their respective platforms. These APIs revolve around the principle of events and streams. Let's check out what these reactive extensions provide. It's time to see the term we just introduced ourselves to, that is, Observables.
Observables are the entities that emit a stream of events. Events can be a button click or checking a checkbox, or some other event like providing input to some device via the interface exposed. There has to be an observer that reacts to whatever value or sequence of values the Observable is emitting. The way observers react to events is by subscribing to the Observable. So these observers subscribing to Observables to react to events is the main theme of ReactiveX. The process in any of the libraries available for different platforms...
