Push notifications use the Apple Push Notifications service (APNs) to deliver notifications to devices. Notifications can display a message, play a distinctive sound, or update a badge on an app’s icon. Push notifications originate from a notification server that you manage and are pushed to your app on a user’s device by the Apple Push Notification service (APNs).
First, you enable push notifications in the Xcode project. Xcode adds the APNs entitlement to your project and the App ID. If necessary, Xcode creates an explicit App ID based on the bundle ID, and for development, an Xcode managed team provisioning profile containing the App ID.
After you enable push notifications, choose whether to communicate with APNs using authentication tokens or communicate with APNs using a TLS certificate, which you configure in your developer account.