ReactJS Tutorial for Beginners

React is the most popular front-end technology that more and more companies are using, and if you are preparing to learn it, this ReactJS tutorial is just the right one for you. Here more than 10 concepts, that will help you in understanding the fundamental concepts of ReactJS.


JSX is a syntax extension to JavaScript. It is used with React to describe what the user interface should look like. By using JSX, we can write HTML structures in the same file that contains JavaScript code.


Components are the building blocks of any React application, and a single app usually consists of multiple components. It splits the user interface into independent, reusable parts that can be processed separately.

Virtual DOM

React keeps a lightweight representation of the real DOM in the memory, and that is known as the virtual DOM. When the state of an object changes, virtual DOM changes only that object in the real DOM, rather than updating all the objects.

One-way data-binding

React’s one-way data binding keeps everything modular and fast. A unidirectional data flow means that when designing a React app, you often nest child components within parent components.

Easy creation of dynamic applications

React makes it easier to create dynamic web applications because it provides less coding and provides more functionality, whereas, with JavaScript applications, code tends to get complex very quickly.

Reusable components

Components are the building blocks of any React application, and a single app usually consists of multiple components. These components have their own logic and controls, and they can be reused through the application, which, in turn, dramatically reduces the development time of an application.

Unidirectional data flow

React follows a unidirectional data flow. This means that when designing a React app, we often nest child components within parent components. And since the data flows in a single direction, it becomes easier to debug errors and know where the problem occurs in an application at the moment.

State in React

The state is a built-in React object that is used to contain data or information about the component. The state in a component can change over time, and whenever it changes, the component re-renders. The change in state can happen as a response to user action or system-generated events. It determines the behavior of the component and how it will render.


Props are short for Properties. It is a React built-in object that stores the value of attributes of a tag and works similarly to HTML attributes. Props provide a way to pass data from one component to another component. Props are passed to the component in the same way as arguments are passed in a function.

Higher-Order Component

A higher-order component acts as a container for other components. This helps to keep components simple and enables re-usability. They are generally used when multiple components have to use a common logic.

React Components Lifecycle

We have learned so far that the React web applications are actually a collection of independent components that run according to the interactions made with them. Each component in React has a life-cycle that you can monitor and change during its three main phases. There are three phases: Mounting, Updating, and Unmounting. You can use life-cycle methods to run a part of code at particular times in the process or application. You can refer to the below diagram to get a visual idea of the life-cycle methods and their interactions in each phase.

Thank you for your time & reading.

Happy Coding…

An IT Graduate, Web Developer