What is the differernce between foreground and background service in Android in terms of code?

Question

Is the following statement correct for Android service - If we call startForeground() inside onStartCommand() or inside onCreate() of the service class then it is a foreground service and if we do not call then it becomes a background service. Here is the code - in this code I am calling the startForeground() method which takes a notification ID and object of a notification class. Now it is a foreground service and if we do not call this method then it becomes a background service. Is this the correct statement? The code is working fine.

class MusicPlayerService : Service() {

    private companion object{
        const val NOTIFICATION_ID = 1
    }


    override fun onCreate() {
        super.onCreate()
        startForeground(NOTIFICATION_ID, createNotification())
    }

   
    override fun onBind(p0: Intent?): IBinder? {
        return null
    }

    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
        //service code
        return START_STICKY
    }

    private fun createNotification() : Notification{
    //Code for creating a notification code           
    }

   

}