This document provides the means for understanding and associating the individual parts of ISO/IEC 11179 and is the foundation for a conceptual understanding of metadata and metadata registries. This document also describes the relationship of ISO/IEC 11179 to other JTC 1/SC 32 standards, technical specifications and technical reports on metadata. In all parts of ISO/IEC 11179, metadata refers to descriptions of data. It does not contain a general treatment of metadata.