The Document Object Modeling (DOM) classes manage XML documents entirely in memory with
support of XML Schema and DTD validation. The classes include the DomDocument, DomNode, and
DomNodeList classes.
The DomDocument class
The DomDocument class provides methods to manipulate a data tree, following the DOM standards.
The DomNode class
The DomNode class provides methods to manipulate a node of a DomDocument object.
The DomNodeList class
The DomNodeList class provides methods to manipulate a list of DomNode objects.