XSD

 XSD (XML Schema Definition), a Recommendation of the World Wide Web Consortium (W3C), specifies how to formally describe the elements in an Extensible Markup Language (XML) document. 

XSD has several advantages over earlier XML schema languages

• it's more direct: XSD, in contrast to the earlier languages, is written in XML, which means that it doesn't require intermediary processing by a parser.
• include self-documentation
•  automatic schema creation
• the ability to be queried through XML Transformations (XSLT).
• supports Inheritance, where one schema can inherit from another schema. it provides the opportunity for re-usability.

• provides the ability to define own data type from the existing data type.

• provides the ability to specify data types for both elements and attributes.