Which option correctly describes data dictionary usage?

• A. A data dictionary defines business terms and their meaning for non-technical users.
• B. A data dictionary defines the data sources and owners.
• C. A data dictionary defines data elements, types, and constraints.
• D. A data dictionary defines data governance policies.

Answer: (C)

The data dictionary is a metadata repository that details each data element used in the system, especially what the element is called, its data type (such as integer, varchar, date), its length or format, and the constraints that apply (like NOT NULL, ranges, allowed values). This precise information about data elements and their constraints provides a single, authoritative reference for anyone working with the data, which helps ensure consistent interpretation and proper validation across databases, reports, and ETL processes.

That’s why describing data elements, their types, and their constraints is the best fit. It directly captures how data is structured and governed at the element level, enabling data quality and proper usage.

Other options describe things that sit alongside or outside the core data dictionary: business terms and meanings are more like a glossary for non-technical users; ownership of data sources and data lineage or governance policies relate to broader metadata catalogs or governance documentation rather than the primary function of a data dictionary.