How to distinguish foreground from background service and what are their main differences?

A foreground service in Android is a service that the user explicitly sees and interacts with, such as a music player with a notification. This service is accompanied by a persistent notification in the panel to prevent the system from killing it due to resource constraints.

A background service operates unnoticed by the user, without a visible interface or notification. It performs tasks in the background, such as data synchronization.

Main differences:

• A foreground service requires displaying a notification and has a higher priority in the system.
• A background service does not display a notification and can be stopped by the system when resources are low.

Example of starting a foreground service with a notification:

val notification = NotificationCompat.Builder(this, CHANNEL_ID)
    .setContentTitle("Service is running")
    .setSmallIcon(R.drawable.ic_service)
    .build()
startForeground(1, notification)