Recovery point objective (RPO):
The amount of acceptable data loss if a recovery needs to be done.
Azure backup solutions have wide variability in their acceptable RPO:
Virtual machine backups usually have an RPO of one day, while database backups have RPOs as low as 15 minutes.
Azure Site Recovery solutions have low RPOs. The DR copy can be behind by a few seconds or a few minutes.
Recovery time objective (RTO):
The amount of time that it takes to complete a recovery or restore.
Azure backup solutions have high RTO’s because of the larger RPO, the amount of data that a backup solution needs to process is typically much higher.
Azure site Recovery solutions have smaller RTOs because they are more in sync with the source.