CertificationGuru - XML Certification Tutorial 4. XML Information Models Purpose Data Control ensure that elements in document follow order Processing document matches a prescribed schema Definition provides a way to define schema Authoring assist authors in creating valid documents Information Models enforce rules.
Rules allow standardized documents.
Standardized documents allow companies to exchange data. Schemas Vs DTDs Schemas support namespaces Schema is written in XML syntax Schemas provide extensive datatype support, whereas, DTDs has very limited datatype support. Schemas have full object oriented extensibility whereas DTDs have extended via string substitutions Schemas are open, closed or refinable content models, whereas, DTDs support closed models only.