juniorReact

What are React components?

Updated Feb 20, 2026

Short answer

In React, components are reusable building blocks of a user interface. Each component represents a part of the UI like a button, header, or page.

Deep explanation

Deep Explanation

A component is a JavaScript function that returns JSX.

Functional component example:

TypeScript
function Header() {
  return <h1>My Website</h1>;
}

You can reuse components like normal HTML tags:

TypeScript
function App() {
  return (
    <div>
      <Header />
      <p>Welcome to the site</p>
    </div>
  );
}

Components help you:

  • Break UI into smaller pieces
  • Reuse code
  • Manage complexity in large apps

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Real-world example

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Common mistakes

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Follow-up questions

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