Assemble the complete stack required to build a modern web app using React: MongoDB (a NoSQL database) and Express (a framework for web application servers), which runs on Node (JavaScript on the server side), complement React very nicely. This book will also cover many other tools that go into building a complete web application: React Router, React-Bootstrap, Redux, Babel, and webpack.

Though the primary focus of Pro MERN Stack is to equip you with all that is required to build a full-fledged web application, a large portion of the book will be devoted to React.

The popular MEAN (MongoDB, Express, AngularJS, Node) stack introduced Single Page Apps (SPAs) and front-end Model-View-Controller (MVC) as new and efficient paradigms. But it has its shortcomings such as lack of support for SEO friendly server-side rendering and being too prescriptive by being a framework.

Facebook's React is a technology that competes indirectly with AngularJS. It is not a full-fledged MVC framework. It is a JavaScript library for building user interfaces (in some sense the View part). Yet, it is possible to build a web app by replacing AngularJS with React – hence the term MERN stack.