MERN is one of several MEAN stack (MongoDB Express Angular Node) variants in which the traditional Angular.js frontend framework is replaced with React.js. MEVN (MongoDB, Express, Vue, Node) is another variant, and really any frontend JavaScript framework can work.Node.js is a popular and powerful JavaScript server platform, and Express.js is a server-side web framework. Regardless of which variant you choose, ME(RVA)N is the best way to work with JavaScript and JSON from start to finish. DURATION:60 days