Web push notifications are enshrined in the W3C standard and define an API for end-user notifications. All browser vendors provide this technology free of charge as part of this standard.
The Push API enables sending a web push notification to a web application via a push service. An application server can send a web push notification anytime and everywhere, even when a web application or user is inactive. The push service ensures reliable and efficient delivery to the user. Web push notifications are delivered to a Service Worker that runs in the origin of the web application, which can use the information in the message to update the local state or display a notification to the user.