The Document Object Model (DOM) is a representation — a model — of a document and its content. [DOM3CORE] The DOM is not just an API; the conformance criteria of HTML implementations are defined, in this specification, in terms of operations on the DOM.
This specification defines the language represented in the DOM by
features together called DOM5 HTML. DOM5 HTML consists of DOM Core
Document nodes and DOM Core
Element nodes, along
with text nodes and other content.
Elements in the DOM represent things; that is, they have intrinsic meaning, also known as semantics.
For example, a
represents a paragraph.
In addition, documents and elements in the DOM host APIs that extend the DOM Core APIs, providing new features to application developers using DOM5 HTML.