What is React and how does it work?

React is an open-source JavaScript library developed by Facebook for building user interfaces — especially dynamic, component-based web apps.

⚙️ How React Works

At its core, React:

1. Uses components — small, reusable UI pieces.
2. Maintains a Virtual DOM — an in-memory representation of the actual DOM.
3. Performs reconciliation — compares the virtual DOM to the real DOM and updates only changed parts.

🧠 Example

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

React converts this JSX into efficient DOM updates behind the scenes, ensuring fast rendering and predictable UI updates.

✅ Summary

React simplifies UI development by letting you describe what you want instead of manually updating how it changes.