Digital Preservation Terms Explained: 20 Essential Concepts for eArchiving

1. OAIS and information packages

OAIS (Open Archival Information System) is a reference model from ISO 14721. It describes an archive as an organisation of people and systems that accepts responsibility for preserving information and making it available to a designated community. OAIS is a model, not a product or a specific technical architecture.

An information package binds a content object to the metadata needed to understand, preserve and prove it. The package model is usually explained through three related terms:

• SIP (Submission Information Package): the package delivered by a producer to the archive.
• AIP (Archival Information Package): the package preserved inside the archive, enriched with preservation metadata, fixity and evidence.
• DIP (Dissemination Information Package): the package or representation delivered to a consumer on request.

Content Information is the data object being preserved together with the information needed to interpret it. That interpretive layer is called Representation Information: format specifications, structure and semantics that turn a bitstream into something meaningful.

2. The people and functions around an archive

A Designated Community is the identified group expected to understand the preserved information. Defining that group makes “understandable in the future” a testable requirement rather than a vague aspiration.

The OAIS functional model names several responsibilities. Ingest is the formal process of accepting information and turning a SIP into an AIP. Archival Storage stores, maintains and retrieves AIPs. Data Management maintains descriptive metadata and internal administrative data. Preservation Planning monitors technology and formats and plans preservation actions before obsolescence becomes an access problem. Access handles consumer requests and produces DIPs.

3. Digital preservation actions

Digital preservation is the set of activities that keeps digital information findable, readable, understandable and trustworthy despite changing technology. It is broader than storage.

Bit preservation keeps the bitstream byte-for-byte unchanged through redundancy, replication, media refresh and fixity checks. Logical preservation keeps the information usable and meaningful through format identification, representation information and preservation actions. Both matter: a perfectly preserved bitstream in a dead format can still be inaccessible.

Significant properties are the characteristics that must survive a preservation action for the object to remain what it is. For an invoice, the amounts and signature may matter more than the original font.

Format obsolescence is the loss of access because current software can no longer render a format correctly. System obsolescence is the loss of access because the hardware, storage or software environment no longer works or is no longer supported.

A preservation action is a deliberate intervention that keeps a preserved object or its metadata accessible and trustworthy. Normalisation converts content proactively to a designated preservation format at ingest. Migration converts it later, typically because the original format is becoming obsolete. Emulation recreates the original software or hardware environment instead of converting the object. Refresh copies data to new media or a newer version of the same format without changing the format itself.

4. Integrity, authenticity and evidence

Integrity means that information is unchanged since capture. Authenticity means that information is what it claims to be and comes from whom it claims. Provenance records the origin of information and what has happened to it since.

Fixity is the property of being demonstrably unchanged, commonly established with a cryptographic hash. A fixity check periodically recomputes and compares hashes to detect silent corruption. A hash is a fixed-length value that changes when the underlying data changes.

A chain of custody is the demonstrable sequence of control from source system through export, ingest, preservation and access, with an artefact at every handover. An audit trail is the chronological, tamper-evident record of who did what to which object and when.

An evidence record is a signed structure that proves the integrity and existence of preserved objects over time. It is the evidence itself, not merely a report about the evidence. An archive timestamp can cover the root hash of a hash tree, while a qualified electronic time stamp is issued by a qualified trust service provider and benefits from the legal framework applicable to qualified trust services.

5. Why the terminology matters

These distinctions help teams ask better questions. Are we only storing bits, or are we preserving meaning? What is the boundary between a repository, an eArchive and Qualified Electronic Archiving? Which metadata and evidence must remain connected to the record? Who is the designated community, and how will future access be tested?

Clear terminology reduces misunderstandings between records managers, archivists, IT teams, legal and compliance stakeholders. It also makes requirements easier to compare across suppliers and jurisdictions.

For a broader overview of governed eArchiving, see Docbyte’s guides to digital archiving, long-term archiving and digital preservation and Qualified Electronic Archiving.