The Redux cycle

Before we start implementing the elements of Redux, let's take a look at the data flow with Redux in one big picture—from an action getting dispatched to the updated application state:

Illustration of the Redux cycle

http://staltz.com/unidirectional-user-interface-architectures.html

An action is dispatched

It all starts with a call to store.dispatch(action), which means that some action happened (user action, request resolved, and so on). An action is a plain object that describes what happened:

{ type: 'CREATE_POST', user: 'dan', text: 'hello world' }

It might help to think of the action as a kind of a log entry that tells we what happened, for example, Post hello...