Understanding Mobile App Notifications (Push, Local, and Background)

Step 1 — Push Notifications

Push notifications are the most common type.

They occur when an event happens on the server, and the server sends a notification to the user’s device through the internet.

For example:

• A friend sends you a message on WhatsApp
• Someone likes your photo on Instagram
• A new video is uploaded on YouTube
• A delivery update appears in Uber or Swiggy

In all of these cases, the event happens on the server first, and then the notification is delivered to your phone.

This is why push notifications are widely used in:

• Chat apps
• Social media platforms
• Delivery apps
• Streaming apps
• E-commerce apps

Whenever something new happens online, push notifications help inform the user immediately.

Step 2 — Local Notifications

Local notifications work differently.

Instead of coming from the internet, they are scheduled directly on the user’s device.

For example:

• A reminder in Google Calendar
• A task notification in Todoist
• A daily habit reminder in TickTick
• An alarm notification

In these cases, the reminder time is already saved on the device.

When that time arrives, the phone itself triggers the notification.

Because everything is stored locally, these notifications can still appear even if the phone has no internet connection.

This makes local notifications very useful for apps that rely on:

• Reminders
• Task scheduling
• Habit tracking
• Offline-first experiences

Step 3 — Background / Silent Notifications

There is another type that many users never notice.

Sometimes apps update their data without showing a visible notification.

For example:

• When you open Gmail, new emails are already synced
• When you open WhatsApp, new messages are already loaded
• News apps often refresh their articles in the background

This happens because the app receives a background notification.

The notification quietly wakes the app and tells it that new data is available.

The app then refreshes its content without interrupting the user.

These notifications are commonly used for:

• Data synchronization
• Feed updates
• Message syncing

Step 4 — Choosing the Right Notification Type

When building an app, the notification type depends on what your app needs to do.

If something happens online and the user should know immediately, apps typically use push notifications.

If the notification is based on a scheduled time or reminder, apps rely on local notifications.

If the app needs to quietly refresh its data, background notifications help keep the app updated.

In real-world applications, it’s very common to use multiple notification types together.

For example:

• WhatsApp

  • Push notifications for new messages
  • Background notifications for syncing chats

• Calendar apps

  • Local notifications for reminders

Understanding these patterns helps developers design apps that communicate effectively with users.