XML Schema Complete Reference, The

E.5. Selected Datatypes Used in Schema Documents

datatype:

A class defined as a simple type. A simple type (or datatype) is, on the one hand, a class that restricts character strings, and, on the other hand, a mapping of those character strings to objects such as numbers or dates or strings. See Chapter 12 for a discussion of all of the datatypes defined in the Schema Recommendation, and Chapter 10 for a discussion of the mechanisms for deriving user-defined simple types from the built-in datatypes.

‘Datatype’ and ‘simple type’ are essentially synonyms. Often in this book we use datatype when talking about the built-in datatypes defined in the Schema Recommendation and ‘simple type’ when talking about user-defined datatypes. Alternatively ...