This tutorial teaches developers how to create a full-fledged web application using React and Express.js, two popular JavaScript frameworks. By following the steps outlined in the tutorial, developers can quickly build a professional-looking app that integrates with third-party APIs. The tutorial covers topics such as setting up a new project, creating an Express backend, making API calls to a Word Associations API, and styling the frontend using React. The example demonstrates how to use Express.js to create a RESTful API and integrate it with a React frontend, showcasing its potential for building powerful web applications.