## TL;DR

The Notifications API allows web pages to display system-level desktop notifications, even when the page is in the background. Permission must be granted by the user via `Notification.requestPermission()`.

## Core Explanation

`new Notification('Title', { body: '...', icon: '...' })`. The `notificationclick` event handler (in service workers) enables actions when users interact with notifications. Notifications API is distinct from the Push API — notifications are local display; Push API enables server-initiated triggers.

## Further Reading

- [Notifications API Living Standard](https://notifications.spec.whatwg.org/)