The MEAN stack is a JavaScript-based framework for developing scalable web applications. The term MEAN is an acronym for MongoDB, Express, Angular, and Node — the four key technologies that make up the layers of the technology stack. MongoDB: A NoSQL, object-oriented database designed for use with cloud applications. One of the greatest advantages of MEAN development is its flexibility. The use of a single programming language (JavaScript) and MongoDB make the stack particularly adaptable. The universal code will run on both the client and the server.