XML Schema Complete Reference, The

5.4. Introduction to Schemas

Similar to the infoset and document information item points of view for abstract documents, there are two points of view for Schemas. The schema set point of view is that a schema is a set of objects generically called “schema components,” with component-valued properties’ values being pointers among the members of the set; the schema component view is that a schema is a particular kind of schema component and all other components of the schema are (recursively) values of component-valued properties of the components.

The Schema Recommendation generally takes the former point of view and does not include a schema schema component in the schema set; nonetheless, it defines a schema schema component and thus implements ...