3-2-1 backup

A foundational data preservation rule designed to protect irreplaceable digital archives from catastrophic loss. The principle requires maintaining three (3) separate copies of your data: the primary working files plus two independent backups. These should be stored across two (2) distinct types of media (for example, an internal solid-state drive and an external network enclosure), with at least one (1) copy kept entirely offsite, such as in secure cloud storage or at a separate physical location. For digital preservation, this multi-layered approach ensures that localized disasters like hardware failure, theft, or fire cannot permanently destroy your master RAW scans and editing history.