In modern web development, one of the most common terms used by developers is ReactJS, which is used by more than 40% of websites to build single-page responsive websites. Now the question arises: What is ReactJS, and why is it so popular? In this article, we are going to explore React in great detail. So let's get started...

What is React.JS?

React is a front-end library for modern web development, built on top of JavaScript. It is an open-source tech stack developed by Facebook. React is used to develop single-page and interactive web pages with significantly fast speed and requires less code as compared to traditional JavaScript.

React apps are built by their fundamental components i.e., components. Components are reusable blocks of code that on their own represent a final state of an application, and when combined together, form a website's user interface.

How does React work?

React works on a single-page application model, commonly known as the SPA model. A single-page application loads only a single HTML document on the first request. Then, it updates the specific component or body of the webpage that needs updating using JavaScript. This approach of routing is known as client-side routing, as in this approach, the server does not need to render new content each time whenever a new request is made by the user, instead this process is done on the client side itself.

If you are coming from the JavaScript background, you might be familiar with DOM. React creates a virtual DOM, which is a copy of the actual DOM. React’s virtual DOM is immediately reloaded to reflect the new change whenever there is a change in the data state. After which, React compares the virtual DOM to the actual DOM to figure out what exactly has changed.

React then figures out the least expensive way to update the actual DOM with the changed state in virtual DOM without rendering the actual DOM. As a result, React’s components and UIs very quickly reflect the changes since you don’t have to reload an entire page every time something updates.

That is it for this blog and I have tried to keep it as simple as possible so that beginners could understand this tech stack in a much more easy way.

If you wanna explore more, this is the official documentation page.