ISO 21961:2003给出了在创建数据实体字典（DED）时使用的规范语言的要求和定义。 数据实体是一个可以或确实具有一个或多个值的概念。数据实体的语义，例如其含义的文本定义，由属性定义。ISO 21961:2003的目的是定义一种语言，用于指定描述数据实体集合语义的词典；它没有定义特定的词典。字典被理解为一种能够以一致且易于理解的方式组织一组信息的机制，人类通常使用字典来查找自然语言中使用的单词的含义。类似地，人类和系统使用数据实体字典（DED）来查找数据产品定义和生成中使用的数据实体的定义和其他属性。 ISO 21961:2003定义了需要传达的语义信息的抽象定义，并以分层方式（属性、实体、词典）呈现规范。这样做的目的是，用于传达信息的实际技术独立于信息内容，因此，相同的抽象标准可以在不同的格式环境中使用。这还允许在跨不同域传输数据时，根据需要将语义信息转换为不同的表示形式。 ISO 21961:2003定义了名称、定义、单位和一小部分其他标准属性的概念，以便在形成数据实体词典时可以一致地使用它们。定义了几类数据实体。这些类允许区分抽象数据实体、模型和具体数据实体，即数据产品中的数据字段。

ISO 21961:2003 gives requirements and defines the syntax of a specification language to be used in the creation of a data entity dictionary (DED). A data entity is a concept that can, or does, take on one or more values. Semantics of a data entity, such as a text definition of its meaning, are defined by attributes. The purpose of ISO 21961:2003 is to define a language for specifying a dictionary which describes semantics for a collection of data entities; it does not define a specific dictionary. A dictionary is understood as a mechanism that is able to organize a set of information in a consistent and easily understandable manner, and it is commonly used by humans to look up the meaning of words used in natural languages. Similarly, a data entity dictionary (DED) is used by humans and systems to look up the definition, and other attributes, of data entities used in the definition and generation of data products. ISO 21961:2003 defines the abstract definition of the semantic information that is required to be conveyed and presents the specification in a layered manner (attributes, entities, dictionaries). This is done so that the actual technique used to convey the information is independent of the information content and, therefore, the same abstract standard can be used within different formatting environments. This also permits the semantic information to be translated to different representations as may be needed when data are transferred across different domains. ISO 21961:2003 defines the concepts of name, definition, units, and a small set of other standard attributes so that they may be used consistently in the formation of data entity dictionaries. Several classes of data entities are defined. These classes allow making a distinction between the abstract data entities, the models, and the concrete data entities, the data fields in a data product.