Glossary · IIoT, data and AI
Metadata
German: Metadaten
In information management, metadata is data that describes other data or resources, such as their meaning, origin, format, units, owner, time stamp, version or classification, so that they can be found, understood, managed and used correctly.
- IIoT
- Technical documentation
In one sentence
Metadata is data about data, such as meaning, source, units, version or classification, that makes resources findable and usable.
Example
Each temperature tag carries metadata for unit, measuring range, asset ID and sensor type, and each manual carries metadata for product, language and version.
Explained in context
Context cards connect this term with others to answer one question. Also in British English and German.
- Every Page is Page One vs. semantic documentationIs Every Page is Page One a form of semantic documentation?UKDeutsch
- Six technical documentation models comparedHow do topic-based, task-based, EPPO, semantic, minimalist and structured documentation differ?UKDeutsch
- Stages of a publishing pipelineWhat happens to structured content inside a publishing SDK?UKDeutsch
How it applies
- Engineering: For process data, metadata such as unit, range, asset and signal source turns a raw value into usable information. Information models such as OPC UA and the Asset Administration Shell (AAS) standardize much of it.
- Operation: Search, filtering and access control all depend on consistent metadata. Inconsistent tag names are one of the most common obstacles in IIoT projects.
- Documentation: Technical documentation uses metadata for product, component, information type, lifecycle phase and audience, for example in iiRDS (iiRDS ProductMetadata). Metadata values should come from controlled vocabularies, not free text.
Metadata vs. data
Whether something is data or metadata depends on the viewpoint: a serial number is data in the ERP and metadata on a service report. What matters is that the describing information is structured, consistent and linked to what it describes.