What Is React?

dev.to React2026-11-01 19:230 views

React is a JavaScript library used to build user interfaces (UI).

It is mainly used to create interactive and dynamic web applications.

For example, websites and applications often have:

React helps developers build and manage these user interfaces more easily.

Why Do We Use React?

When building a large website using only HTML, CSS, and JavaScript, managing the code can become difficult.

React helps by dividing the user interface into smaller, reusable parts called components.

For example:

Website │ ├── Navbar ├── Product List │ ├── Product Card │ ├── Product Card │ └── Product Card │ └── Footer

Each part can be created as a separate component.

A component is a reusable piece of the user interface.

For example:

function Welcome() { return <h1>Hello, World!</h1>; }

This creates a simple React component.

We can use components to build different parts of a website.

React commonly uses JSX.

JSX allows us to write HTML-like code inside JavaScript.

Example:

function App() { return <h1>Hello, React!</h1>; }

Although it looks similar to HTML, JSX is written inside JavaScript.

React helps update the user interface when data changes.

For example, if a user clicks a button and a value changes, React can update the relevant part of the screen.

This makes it useful for building interactive applications.

React can be used to build:

Source：https://dev.to/lokesh_a/what-is-react-3c91