Kumar Harsh's tutorial outlines the process of integrating Descope, a no-code authentication platform, into a React application to streamline user authentication and authorization without writing extensive authentication code. The tutorial demonstrates setting up passwordless logins and secure access control by configuring Descope's authentication flows and establishing user roles, specifically for students and teachers. A demo project is created where students can view questions and teachers can access questions and their answers, facilitated by a backend built with Node.js and a PostgreSQL database. The guide provides detailed steps for initializing the Descope SDK in the React app, setting up the backend server to manage user sessions and roles, and configuring a PostgreSQL database to store the questions and answers. The tutorial concludes by highlighting the seamless role-based access control enabled through Descope, with changes in user roles reflected in real-time within the app.