data dictionary

A directory of information about the definition, structure, and usage of data that does not contain the data itself but contains the name of each data element, its definition, where and how it is used, and its relationship to other data

Information on the definition, structure, and usage of data within a system or organization. See also metadata and documentation.

A catalog of all data held in a database, or a list of items giving data names and structures. Also referred to as DD/D for data dictionary/directory. Commercial RDBMSs have online data dictionaries stored in special tables called system tables.

A part of a database management system that provides a centralized repository of information about data in a database, such as meaning, relationship to other data. 2. An inventory that describes, defines, and lists all of the data elements that are stored in a database.