Apple Push Notification service

Apple Push Notification Service (APNs) is a cloud-based system that delivers short messages or alerts from apps or services to your Apple devices like iPhones and iPads. When an app wants to notify you—such as sending a new message, alert, or update—it sends the information through APNs, which securely routes it to your device. This process allows you to receive timely notifications even when the app isn't open, ensuring you stay informed without activating the app continuously. Think of APNs as the delivery network that efficiently and securely conveys notifications from developers to your Apple devices.