Introduction to React

React is a JavaScript library for building user interfaces, primarily for single-page applications. It's used for handling the view layer for web and mobile apps. React allows you to design simple views for each state in your application.

How to Install React

First, you need to have Node.js and npm (Node Package Manager) installed. Once you have these installed, you can set up a React application by first installing the create-react-app command line tool:

npm install -g create-react-app

After that, you can create a new application by running:

create-react-app my-app

This will set up a new React application named "my-app". You can start the application by navigating into the directory and running npm start.

For more details, see the official React documentation.

React Components

Components are the building blocks of any React application, and a single app usually consists of multiple components. A component is essentially a piece of the user interface.

Here's an example of a simple React component:

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

This is a simple component called "Welcome" that returns an HTML heading. You can use this component in other parts of your application like this:

function App() {
  return <Welcome name="Sara" />;
}

This would display "Hello, Sara" on the page.