Reactive Programming can be used to build a Reactive System. By definition, Reactive Programming is a programming practice or pattern that is aligned around the data flow and the propagation of the changes. The changes in data are automatically propagated by the underlying execution model through the data flow.
To make it simple, Reactive Programming is a way to handle asynchronous data streams in a more effective manner. In other words, it is programming dealing with an asynchronous data stream, or it can be called the subset of asynchronous programming. Reactive Programming is a way of execution where new information will push the flow forward, rather than having the flow controlled by an execution thread.
The data stream is a series of business events that happen during the system execution, such as various keyboard or mouse events, HTML field...
