• Chapter 1: Getting Started with Stylus Studio®
• Chapter 2: Editing and Querying XML
• Chapter 3: Converting Non-XML Files to XML
• Chapter 4: Working with XSLT
• Chapter 5: Creating XSLT Using the XSLT Mapper
• Chapter 6: Debugging Stylesheets
• Chapter 7: Defining XML Schemas
  • What Is an XML Schema?
    • Reference Information
  • Creating an XML Schema in Stylus Studio
  • Working with XML Schema in Stylus Studio
  • Getting Started with XML Schema in the Tree View
  • Defining simpleTypes in XML Schemas
  • Defining complexTypes in XML Schemas
  • Defining Elements and Attributes in XML Schemas
  • Defining Groups of Elements and Attributes in XML Schemas
  • Adding Comments, Annotation, and Documentation Nodes to XML Schemas
  • Defining Notations
  • Referencing External XML Schemas
  • Generating Documentation for XML Schema
  • Generating JAXB Classes
  • About XML Schema Properties
• Chapter 8: Defining Document Type Definitions
• Chapter 9: Writing XPath Expressions
• Chapter 10: Working with XQuery in Stylus Studio
• Chapter 11: Composing Web Service Calls
• Chapter 12: Accessing Relational Data as XML
• Chapter 13: Integrating with Third-Party File Systems
• Chapter 14: Extending Stylus Studio
• Chapter 15: Stylus Studio GUI Reference

Home > Online Product Documentation > Table of Contents > What Is an XML Schema?

What Is an XML Schema?

An XML Schema conforms with the W3C XML Schema Recommendation. The XML Schema Recommendation defines an XML markup vocabulary for specifying the structure of an XML document. An XML Schema serves the same purpose as a DTD. The most visible difference is that an XML Schema is in XML, while a DTD is not.

Like a DTD, an XML Schema describes the structure of a document. However, an XML Schema contains more specialized types of nodes than a DTD schema. For example, in an XML Schema, you can define nodes of type group and attributeGroup. These nodes contain groups of elements and attributes, respectively.

In an XML Schema, elements that contain subelements or attributes are called complexTypes. Elements that contain data but do not contain subelements or attributes are simpleTypes. Attributes are always simpleTypes. In your XML Schema, along with elements and attributes, you define complexTypes and some simpleTypes. In addition, many simpleTypes are part of the XML Schema grammar.