What is React used for?

React is a JavaScript library for building user interfaces, especially single-page applications (SPA). It allows you to build UI declaratively and component-based, meaning the interface is broken down into independent, reusable components.

Main advantages of React:

• Declarative: you describe how the UI should look based on the state, and React updates the DOM automatically.
• Component-based approach: UI is built from small parts, which makes maintenance and reuse easier.
• Virtual DOM: React efficiently updates only the changed parts of the page, improving performance.

Example of a simple React component:

function Hello(props) {
  return <h1>Hello, {props.name}!</h1>;
}

// Usage
<Hello name="World" />