Explanation
Scenario: Ensure that all the virtual machines for App1 are protected by backups.
You can back up Azure VMs using a couple of methods:
Single Azure VM: You can back up an Azure VM directly from the VM settings.
Multiple Azure VMs: You can set up a Recovery Services vault and configure backup for multiple Azure VMs.
References:
https://docs.microsoft.com/en-us/azure/backup/backup-azure-vms-first-look-arm