Reference Data is a specialized subset of data used to categorize, define, and standardize other data, providing critical context for interpreting master and transactional data. It includes controlled vocabularies, classification schemes, code lists, taxonomies, ontologies, and cross-reference datasets that support consistent and accurate data usage across systems and processes. Reference Data is typically stable over time and governed to ensure accuracy, relevancy, and adherence to organizational and industry standards. Examples include country codes, currency codes, product classifications, and mappings between equivalent values, all of which facilitate interoperability, data integrity, and efficient communication within and between organizations.