Web push notifications allow users to sign up for timely updates to websites they love, and you can effectively reconnect them with customized, relevant content.
The Push API gives Progressive Web Applications the ability to receive notifications sent from a server. This also works if the Web Application itself is not in the foreground or is currently loaded. This enables Developers to send asynchronous notes and updates to users who have signed up for them.
The result is a better and a more active engagement with current content.