The document discusses the MEAN and MERN application stacks. MEAN uses MongoDB, Express, AngularJS, and Node.js while MERN uses MongoDB, Express, React, and Node.js. It describes the components of each stack including MongoDB for data storage, Node.js for the application backend, and either AngularJS or React for the frontend. It also discusses how these stacks enable building applications with universal JavaScript and REST APIs for rapid development and scalability.