Stack means using the database and web server in the back end, in the middle you will have logic and control for the application and interaction of user at the front end.
MongoDB − Database System
Express − Back-end Web Framework
Node.js − Web Server Platform
AngularJS − Front-end Framework
MEAN name was coined by Valeri Karpov, a MongoDB developer.
It is an open source framework which is free to use.
It can be used as standalone solution in a whole application.
It provides lower development cost and increases the developer flexibility and efficiency.
It supports MVC pattern and uses the JSON for transferring data.
It provides additional frameworks, libraries and reusable modules to increase the development speed.
Before we begin with further concepts, we will see the basic building blocks of MEAN.JS application.
In MEAN acronym, E stands for Express, which is a flexible Node.js web application framework used to make development process easier. It is easy to configure and customize, that allows building secure, modular and fast applications. It specifies the routes of an application depending on the HTTP methods and URLs. You can connect to databases such as MongoDB, MySQL, Redis easily. For more information, refer to this link Express.