The MERN stack is a powerful, full-stack JavaScript solution for developing modern web applications. It comprises four main technologies: MongoDB for the database, providing a flexible, document-oriented data structure; Express.js as the backend framework, streamlining server-side development with robust APIs and middleware; React for the front-end, enabling developers to build dynamic, interactive user interfaces with reusable components; and Node.js as the runtime environment, allowing JavaScript to be used for server-side scripting.
Together, these technologies create a seamless development experience, enabling developers to build scalable, high-performance applications using a single programming language, JavaScript, across both the front and back ends.