What is MERN Stack & How Does It Works?

Web application development is not the same anymore as it was a couple of years back. Web applications are developed using a multitude of technologies. And nowadays, there are multiple options available for web application development that many developers often get confused with.

The confusion is not only about the broad stack (the combination of technologies for web development) but also about the tools that help in development. So, in this article, we will discuss and learn what MERN Stack is and why it is being used by developers for web applications development.

What is MERN Stack?

MERN Stack is an umbrella term used for MongoDB, Express, React and Node.js. MERN stack is an open-source full-stack JavaScript solution used for faster and easier development and deployment of full-stack applications. MERN is designed to make the process of application development swift and simple.

Each component of MERN has its own role that we must understand. So let’s take a peek at them.

1. MongoDB: Cross-platform Document-Oriented Database

MongoDB is a cross-platform source available document-oriented database program. It is a NoSQL database that used JSON documents with schemas (optional). MongoDB is flexible and its document model outlines the object in the code, making data effortless to work with. Also, being distributed at its core, MongoDB has horizontal scaling, high availability, end-to-end security, management tooling, and geographic distribution.

2. Express: Back End Framework

Express or Express.js is a backend web application framework used for Node.js. It offers multiple features to make web application development easier and faster which otherwise takes more time only using Node.js. Express can be configured and customized efficiently. It helps a developer to define application routes based on HTTP and URLs. Express consists of many middleware components to support additional tasks. Express makes it easier to serve static resources and files of your application.

Read: Best Practices for Testing APIs

3. React: Front End Library

React is an open-source and free frontend JavaScript library released by Facebook. It is used for building interactive UI (user interface) of web applications. It handles the view layer and can be used to develop both mobile and web applications. React enables developers to form encapsulated segments that maintain their state and then comprise them to make complicated interfaces. Using Node, React also renders on the server.

4. Node.js: JS Runtime Environment

Node.js is a cross-platform and open-source back end JavaScript runtime environment. Node.js works on V8 engines and run JS code outward of a web browser. With Node.js, a developer can generate dynamic content for web pages, collect form data, modify data in the database and manage files on the server. Node.js runs a single process without creating new threads for each request. It also provides a set of I/O primitives in its library to prevent JS code from blocking.

How Does MERN Stack Works?

As from the above explanation, all the components of MERN can be used individually, however, by combining these technologies, a developer can accomplish excellently performing web applications. So in this section, we will understand how the MERN stack works.

To help you understand the complete mechanism, let’s take an example. Assume that you have developed an e-commerce web application for clothes. Now, a customer visits the web app to shop for a t-shirt. So from the link provided on the web page, the user reaches the t-shirt page. But how we will get data from the backend?

• User visits our react based landing page.

• The user clicks on the link to buy a t-shirt. And the t-shirt page is rendered without reloading the page as it is a single-page application.

• But at this point, we do not have any data on the t-shirt, that is, the state is empty. So, we will make an API call to fetch the data from the backend.

• As the data fetching process is asynchronous it will take more time. In the meantime, we will show a loading GIF to the user.

• While at the backend, the ExpressJS looks the endpoint that has been hit and execute the related controller function to retrieve the data.

• In the controller, we can use mongoose to query the database, get the data and return it in JSON format.

• JSON data is then sent back to React where the state is updated with the fetched data.

• WIth the updated state, React will re-render the component and replace loading GIF with the t-shirt information.

So, that’s how MongoDB, React, Express and node work together.

Why Use MERN Stack?

MERN Stack is undoubtedly a great choice for developers, to answer why here are a few reasons:

• MERN provides a full-stack development environment that helps in end-to-end development.

• MERN supports Model View Controller (MVC) architecture, which supports developers to build workflow easily.

• MERN comes with its suite of testing tools to make identify errors effortlessly.

• As every line of code in MERN is written in JavaScript whether it’s for the client-side or server-side, it becomes easier for developers to integrate and work on different frameworks easily.

• MongoDB greatly works with Node.js and makes storing, representing and manipulating JSON data of the web app easier.

• Express wraps HTTP requests and responses to map URLs for the functionality of server-side.

• React helps in developing interactive UI in HTML and interacting with the remote servers.

• The entire combination supports JSON data to flow from front to back easily while making it faster to build and efficient to debug.

Final Thoughts

Like any other stack, you can use the MERN stack to build any application you want. Although it is ideally used where the application is cloud-native, JSON-heavy, and need dynamic web interfaces like Todo apps, workflow management, interactive forums and social products.

So, if you want to develop an app that is cost-effective, open-source, and offers better performance and UI rendering, you can always opt for the MERN stack. And if you are a business looking for a MERN-based web application, you can hire MERN developers who have relevant experience and knowledge.