Nodes That Simplify Schema Creation
The nodes that simplify schema creation is a miscellaneous category for two node types that defy categorization into the other categories, and which simplify the creation of schema. The first such node, the Schema node, corresponds to the schema element in XML Schema definition (XSD) language, which is the element that serves as the outermost element in all XSD schemas.
The other simplification node plays a more significant role in this regard. The Attribute Group node corresponds directly to the attributeGroup element in XSD, and provides a mechanism for defining a group of related attributes, which always occur together, in a single location and then using that group definition in multiple locations throughout the schema. The remainder of this section provides additional information about these nodes.