What is an XML Schema?

The purpose of an XML Schema is to define the legal building blocks of an XML document, just like a DTD.

an xml schema:

• defines elements that can appear in a document
• defines attributes that can appear in a document
• defines which elements are child elements
• defines the order of child elements
• defines the number of child elements
• defines whether an element is empty or can include text
• defines data types for elements and attributes
• defines default and fixed values for elements and attributes to
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