Introduction to XML Schema

An XML schema describes the structure of an XML document.

XML SCHEMA is used to describe and validate the structure and the content of XML data.

Learn These Before Starting : Recommended

Should have a basic understanding of the following Languages : (You can Learn From our Repository)

• HTML
• XML and XML Namespaces
• A basic understanding of DTD

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:

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

XML Schemas are the Successors of DTDs

We think that very soon XML Schemas will be used in most Web applications as a replacement for DTDs. Here are some reasons:

• XML Schemas are extensible to future additions
• XML Schemas are richer and more powerful than DTDs
• XML Schemas are written in XML
• XML Schemas support data types
• XML Schemas support namespaces