# Long-Term Digital Preservation **Domain:** Digital Preservation / Continuity Infrastructure **Doc Type:** Canonical Preservation Hub **Maturity:** Established Practice / Prospective Application ## Definition **Long-term digital preservation is the continuing work required to keep digital information authentic, understandable and usable across changes in media, formats, software, institutions and threat environments.** It is an active process, not passive storage. ## Preservation Functions Functions include fixity checking, redundant storage, documented custody, format and media migration, preservation metadata, audit trails, risk monitoring, recovery testing and retention of the knowledge needed to interpret the object. Significant properties must be identified because a technically readable object can lose the behavior or context that made it meaningful. ## Continuity Boundary These methods are necessary for continuity-bearing state but not sufficient for a person. An archive may preserve records and executable artifacts while no subject is running. [[wiki/Executable Preservation|Executable Preservation]] adds interpreters and environments. [[wiki/Continuity Service Tiers|Continuity Service Tiers]] separates cold preservation, warm readiness and hot execution. [[wiki/Continuity Disposition|Continuity Disposition]] supplies the authority boundary. Permission to preserve an archive does not imply permission to assemble a person-model, and permission to reconstruct does not imply permission to activate. Preservation metadata should record the applicable election and its version without exposing private directive content more broadly than necessary. Preservation actions can also alter identity-bearing state. Every migration and repair should enter the [[wiki/Digital Thread|Digital Thread]] and remain available for audit. ## Sources / Provenance - [U.S. National Archives: Digital Preservation](https://www.archives.gov/preservation/digital-preservation/about). - [U.S. National Archives: Digital Preservation Risk](https://www.archives.gov/preservation/digital-preservation/risk). - [[wiki/Open Archival Information System|Open Archival Information System]]. ## Key Insight **Digital preservation is successful only when future custodians can verify, understand and use what survived.**