datadefinition

Datadefinition is the specification that describes the characteristics of data used within an information system or enterprise data environment. It encompasses the precise meaning of data elements, their data types, allowed values, formats, constraints, and relationships, as well as their origin, ownership, and lifecycle. In practice, datadefinition is a foundational component of data governance, data modeling, and database design, and is often embodied in a data dictionary or metadata registry.

A typical data definition includes: element name, label, data type, length or precision, nullability, default value, valid value sets, constraints, units of measure, derived rules, and relationships to other elements such as keys. It may also specify permissible transformations and lineage information, source system, data steward, and ownership.

Datadefinition supports consistency and interoperability by providing a shared vocabulary and unambiguous rules for data usage. It enhances data quality, data integration, reporting, and API design, and supports impact assessment when systems evolve. It is commonly maintained as part of a data dictionary or metadata repository and is managed through change control and versioning.

In practice, datadefinition interacts with related concepts such as data modeling, schemas, metadata management, and data governance. Challenges include keeping definitions up to date across heterogeneous systems, resolving semantic gaps, and balancing specificity with reuse.