The DOM is a W3C (World Wide Web Consortium) standard.
The DOM defines a standard for accessing documents like XML and HTML:"The W3C Document Object Model (DOM) is a platform
and language-neutral interface that allows programs and scripts to dynamically access and update the content, structure, and style of a document."
The DOM is separated into 3 different parts / levels:
Core DOM - standard model for any structured document
XML DOM - standard model for XML documents
HTML DOM - standard model for HTML documents
The DOM defines the objects and properties of all document elements, and the methods (interface) to access them.