Glossary
Recovery time objective (RTO)
The target time to restore a system after an incident. On paper for most companies; fiction during a real one.
Recovery time objective is how long you have decided a system can be down before the impact is unacceptable. Four hours, one business day, whatever the document says. The number matters because downtime cost scales linearly with it.
The catch is that most RTOs are aspirational. During a real ransomware event the team discovers restores run at a crawl, the last good backup is older than they thought, or everything depends on Active Directory coming back clean first. An RTO you have never tested with a full restore is a guess. Why downtime is the cost nobody budgets, and what immutable backups do about it.