RPO looks backward. RTO looks forward.
These are business tolerances expressed in time. They are not arbitrary engineering preferences.
RPO
Data loss window
RTO
Downtime window
Time example
09:00Last recoverable backup
09:45Disaster hits production
10:00Failover decision and restore start
11:10Apps and data validated
11:30Traffic restored
Memory line
RPO = rewind distance
If the last clean state is 45 minutes old, the business may lose up to 45 minutes of work.
Memory line
RTO = screen-black time
If service returns in 100 minutes, actual recovery time is 100 minutes.