What is public/manifest.json file in create-react-app?

I know that chrome extensions use 'manifest.json`, but here, it is used as something else as well.

contents -

{
  "short_name": "React App",
  "name": "Create React App Sample",
  "icons": [
    {
      "src": "favicon.ico",
      "sizes": "192x192",
      "type": "image/png"
    }
  ],
  "start_url": "./index.html",
  "display": "standalone",
  "theme_color": "#000000",
  "background_color": "#ffffff"
}

When I change some value, page update, but nothing changes.

It's a Web App Manifest that describes your application and it's used by e.g. mobile phones if a shortcut is added to the homescreen.

From MDN (linked above):

The web app manifest provides information about an application (such as name, author, icon, and description) in a JSON text file. The purpose of the manifest is to install web applications to the homescreen of a device, providing users with quicker access and a richer experience.

manifest.json is the json file that is mostly used to describe our app On mobile phones