Understanding React, Flux, and Redux: A Frontend Architecture Guide

React

React is a view‑layer framework used to render UI. It mainly provides:

Componentization

One‑way data flow via props View updates driven by state changes

Virtual DOM to improve rendering performance

State changes are usually triggered by user interactions on the page. Each component has a setState method to modify its own state, but as applications grow, managing the relationship between many states and many views becomes difficult.

Flux

Flux is an application architecture (or mindset) that can be used with React or other frameworks. It centralizes the handling of all actions that cause state changes. Flux maintains one or more Store objects (similar to the Model in MVC) that hold all application data.

When an event occurs, Flux processes the event, updates the relevant Store, and the root (or controller) view reads the new Store data, updates its state, and passes the new state down through React’s one‑way data flow to refresh the UI.

Flux’s conceptual model:

Flux consists of four parts: Dispatcher, Store, View, and Action. The Dispatcher is the core hub that receives Actions, distributes them to all registered Stores, and triggers Store change events. Controller‑views listen for these changes, fetch updated data from the Stores, call setState, and re‑render themselves and their descendants. This centralization makes testing easier because actions can be fabricated and dispatched without a real UI event.

Redux

Redux serves the same purpose as Flux but implements it differently.

1. Single Store – Redux consolidates multiple stores into a single global store, from which the entire application state can be derived. Update logic resides in pure functions called reducers rather than inside the store itself.

2. No Dispatcher – Redux replaces the Dispatcher with reducers. A reducer is a pure function expressed as (previousState, action) => newState. Multiple reducers manage different slices of the state tree and are combined with combineReducers into a root reducer that produces the new global state.

When an Action is dispatched, the store calls each reducer; the reducers return a new state, which the store then provides to the view layer.

Key visual differences:

Flux store structure:

Redux store (or reducer) structure: