What does the term “Structure” refer to?

When describing GJXDM and NIEM, the term "structure" is often used, but what is really meant by that? In this case, structure refers to the representation of data dictionary entities in XML Schema. The key factors to remember are:

• Data model types become XML Schema types.
• Properties become XML elements and attributes.
• Data model type inheritance becomes XML Schema type inheritance.
• Duplication of entities is avoided by using references

The important concept here is the transition of the underlying data model hierarchy to the representation of objects in the XML schemas (GJXDM and NIEM) as elements and attributes.