MongoDB
MongoDB is an open source, NoSQL database designed for cloud applications. It uses object-oriented organization instead of a relational model. In the MEAN stack, MongoDB is the home of all of the application data. Because Mongo operates in JavaScript along with the application proper, there’s no need to translate the object as it journeys from the application to the database and back. This means the process is streamlined between front and back of house, making the application seamless.
Express
Express is a web application framework for Node.js, operating as the back-end of the MEAN stack. This means Express manages all interactions between the front-end and the database, providing smooth access and transfer of data to the end user. Since the framework was built with Node functionality in mind, it likewise ensures uniformity in the stack and easier work between the tools.
AngularJS
The gold standard of JavaScript front-end frameworks, Angular is increasingly popular for a variety of reasons. It offers the ability to develop simultaneously for front-end and back-end use, it includes a variety of easy-to-use templates, and the ever-growing numbers of users mean that the application itself has been improved and optimized into a well-oiled development machine.
Node.js
Node.js is an open source JavaScript framework that uses asynchronous events to process multiple connections simultaneously. It is an ideal framework for a cloud-based application, as it can effortlessly scale requests on demand. Node.js is rapidly becoming the standard through most major web applications dealing with massive or unpredictable spikes in volume or customer requests.