This document provides an introduction to Flux, describing it as an architecture pattern for one-way data binding that is framework agnostic. It explains the key components of Flux including Stores, Actions, Dispatcher, Smart Components, and Dumb Components. Stores contain the application state, Actions are used to invoke state changes by passing arguments to the Dispatcher, and there is only one Dispatcher. Smart Components are aware of the Store and listen for changes, while Dumb Components only display data passed in via props. Examples of when to use Flux include for single page apps and complex UIs, while simpler components or static sites may not need it. Redux is recommended as a common Flux implementation.