Process XML Data Using the XPath Data Model
The XPathDocument class provides a fast, read-only, in-memory representation of an XML document using the XPath data model. The XmlDocument class provides an editable in-memory representation of an XML document implementing W3C Document Object Model (DOM) Level 1 Core and Core DOM Level 2. Both classes implement the IXPathNavigable interface and return an XPathNavigator object used to select, evaluate, navigate, and in some cases, edit the underlying XML data.
The following sections describe the functionality of the XPathNavigator class based on the class that returns it.