A service worker is a script that your browser runs in the background, separate from a web page, opening the door to features that don't need a web page or user interaction. Today, they already include features like push notifications and background sync. In the future, service workers might support other things like periodic sync or geofencing. The core feature discussed in this tutorial is the ability to intercept and handle network requests, including programmatically managing a cache of responses.

![lifecycle] (https://developers.google.com/web/fundamentals/primers/service-workers/images/sw-lifecycle.png)

• you need HTTPS

navigator.serviceWorker.register('/sw.js')
  .then((registration) => {
    // Registration was successful
    console.log('ServiceWorker registration successful with scope: ', registration.scope);
  }
});