How does React handle server-side rendering?

Server-side rendering (SSR) is the process of rendering a JavaScript application on the server and sending the fully-rendered HTML to the browser. React supports server-side rendering, which allows you to render your React components on the server and send the generated HTML to the browser. This can improve the performance of your application by reducing the time it takes for the initial load, and by making it more SEO-friendly.

In order to use server-side rendering in React, you will need to use a library or framework that is designed to work with React, such as Next.js, or you can use a package like React-Router to set up SSR.

The basic process of server-side rendering in React is as follows:

1. The browser makes a request to the server for the initial page load.
2. The server receives the request and renders the React components to a string of HTML.
3. The server sends the rendered HTML back to the browser.
4. The browser receives the HTML and renders the page.
5. The JavaScript bundle for the React application is then loaded, and the React components are hydrated, connecting the JavaScript representations of the components to the rendered HTML.

Once the JavaScript bundle is loaded, the application can continue to run as a single-page application, with all further interactions handled by React on the client side.

It's important to note that server-side rendering comes with some additional complexity and setup effort, but it can be a great way to improve the performance and SEO of your application if it's needed.