This course is focused on implementing authentication in applications built with the MERN stack—MongoDB, Express.js, React, and Node.js. It explains the principles of securing a MERN application by managing users, encrypting passwords, and generating tokens for session handling. The course examines how to set up authentication middleware in Express.js to protect routes and how to use JSON Web Tokens (JWT) for maintaining user sessions. Participants learn to build login and registration components in React, connect them to a Node.js backend, and handle user authentication state. It also covers best practices for securely storing sensitive information in MongoDB and deploying authenticated applications. By the end of the course, students are capable of creating secure MERN stack applications with robust user authentication systems.