This section provides detailed reference documentation for working with React. For an introduction to React, please visit the Learn section.

The React reference documentation is broken down into functional subsections:

Programmatic React features:

• Hooks - Use different React features from your components.
• Components - Built-in components that you can use in your JSX.
• APIs - APIs that are useful for defining components.
• Directives - Provide instructions to bundlers compatible with React Server Components.

React-dom contains features that are only supported for web applications (which run in the browser DOM environment). This section is broken into the following:

• Hooks - Hooks for web applications which run in the browser DOM environment.
• Components - React supports all of the browser built-in HTML and SVG components.
• APIs - The react-dom package contains methods supported only in web applications.
• Client APIs - The react-dom/client APIs let you render React components on the client (in the browser).
• Server APIs - The react-dom/server APIs let you render React components to HTML on the server.

React has idioms — or rules — for how to express patterns in a way that is easy to understand and yields high-quality applications:

• Components and Hooks must be pure – Purity makes your code easier to understand, debug, and allows React to automatically optimize your components and hooks correctly.
• React calls Components and Hooks – React is responsible for rendering components and hooks when necessary to optimize the user experience.
• Rules of Hooks – Hooks are defined using JavaScript functions, but they represent a special type of reusable UI logic with restrictions on where they can be called.

• Legacy APIs - Exported from the react package, but not recommended for use in newly written code.