MERN Stack is a popular JavaScript-based full stack development framework used to build dynamic and scalable web applications. MERN stands for MongoDB, Express.js, React.js, and Node.js. This stack allows developers to work seamlessly across front-end and back-end using a single language — JavaScript. With React handling the UI, Node.js and Express managing server-side logic, and MongoDB as the NoSQL database, MERN is ideal for building fast, modern, and responsive web applications.

MEAN Stack is another powerful full stack development framework based entirely on JavaScript, widely used to build enterprise-grade web applications. MEAN stands for MongoDB, Express.js, Angular, and Node.js. Angular is used for the front-end development, offering a component-based structure, while Node.js and Express power the back-end and MongoDB handles the database. MEAN provides a robust architecture suitable for real-time applications and scalable systems.