Push Notification is a notification that is forcibly sent by the server to the client so that the notification sent to the client without waiting for the client to request it. In order for the notification to be accepted by the client, the client and server must always be connected through socket communication.

This tutorial will guide you through how to add mobile push notifications to an iOS Swift chat application. You'll be using PubNub to construct and send push notification payloads to the Apple Push Notification Service (APNs) to deliver the notifications to your device.

Notification system for sending SMS, Email, and Mobile push notifications