The value() method is used to obtain a single value from the XML document data.
The XML native data type can be used since SQL Server 2005 to parse XML and produce a rowset replacing the use of the OPENXML rowset provider.
Transact-SQL supports a subset of the XQuery language that is used for querying the XML data type.
Description of how to generate XML instances and and XML is stored in the SQL Server.
SQL Server XQuery extension methods in order to bind the non-XML relational data inside XML.
XPath uses path expressions to select nodes in an XML document. The node is selected by following a path or steps.