Express.js is a robust defacto standard application development backend framework

Express.js is the most popular Node.js framework and has been for a while now. It’s easy to use, lightweight, and flexible. It also offers a huge selection of community-created plugins to add functionality to your application.

It is built on top of Node’s core modules, HTTP, HTTPS and path, so you can use it as a middleware layer between your application and the server.

As a web application framework, Express provides a set of features that make it easier to build web applications quickly using the Node.js platform. We can also create APIs that uses MongoDB or other databases.