This section provides a quick description of what is XSD (XML Schema Definition) - a language to define rules to validate XML documents.
What is XSD (XML Schema Definition)?
XSD (XML Schema Definition) is an XML schema language recommended by W3C (World Wide Web Consortium).
An XML schema is a set of rules to which an XML document must conform in order to be considered 'valid'
according to that schema. An XML schema language is a set of rules on how to write an XML schema.
The current version (last modification date: 5 April 2012) XSD is 1.1
Its specifications are divided into 2 parts and available at W3C web site: http://www.w3.org/XML/Schema:
W3C XML Schema Definition Language (XSD) 1.1 Part 1: Structures -
Sets out the structural part of the XSD Language.
W3C XML Schema Definition Language (XSD) 1.1 Part 2: Datatypes -
Define datatypes to be used in the XSD Language.
Some quick notes on XSD 1.1:
XSD 1.1 is superset of XML Schema 1.0.
XSD 1.1 is designed to validate XML 1.1 and XML 1.0 documents.
XSD 1.1 validation rules are written in XML documents.
XML 1.1 supports its own datatypes.
The previous version (last modification date: October 28, 2004) XSD was called XML Schema 1.0.
Its specifications are divided into 3 parts and available at W3C web site: http://www.w3.org/XML/Schema:
XML Schema Part 0: Primer - An easily readable description of XML Schema
and a quick tutorial on how to write XML schema documents using XML Schema.
XML Schema Part 1: Structures - A set of rules specifying the XML Schema definition language,
which offers facilities for describing the structure and constraining the contents of XML 1.0 documents.
XML Schema Part 2: Datatypes - A set of rules specifying datatypes to be used in XML Schema.