Final answer:
The 3-2-1 rule is a backup strategy that involves keeping three copies of your data on two different kinds of media, with one copy stored offsite for disaster recovery.
Step-by-step explanation:
You asked about the 3-2-1 backup rule, a fundamental strategy in data backup and disaster recovery. This rule suggests you should keep three copies of your data, store them on at least two different kinds of media, and keep one backup copy offsite. The purpose of having an offsite copy is to protect against the possibility of a local disaster, such as a fire or burglary, which could destroy onsite copies.
The 3-2-1 rule is widely regarded as a best practice in the data protection and IT industries, ensuring that even if one or two backups fail, there will still be an intact copy of the data available to restore. Implementing such a strategy is a key step toward comprehensive risk management for personal data or business-critical information.