DOM stands for Document Object Model. It's mostly used in correlation with HTML and XHTML. The DOM allows you to generate web pages dynamically, traverse the components of a web page, and change the components of a web page. DOM has also been used in correlation with rich media documents, including Microsoft Word and OpenOffice.org documents. Basically it boils down to exactly what D-O-M stands for and can be abstracted for any object-based system.