REDUX FLUX
Redux is a container for JavaScript apps. Flux is a container for application state and logic that are registered to callbacks.
It offers interesting features such as writing applications, testing in different environments such as a server, client, etc. It is an observer pattern that is modified to fit React.
In redux, actions can be functions or promises. It is a fancy name given to observer pattern and Facebook has developed tools to aid the implementation of these patterns.
Redux is the first choice for web developers because it offers live code editing. Flux supports actions that are simple JavaScript objects.