DOM Tree

A programming interface that represents an HTML or XML document as a hierarchical tree structure, where each node corresponds to a part of the document such as an element, attribute, or text content. Web browsers construct the DOM tree from HTML source code, and assistive technologies like screen readers use it to understand and present page content to users. The quality of the DOM tree directly affects accessibility: well-structured HTML with semantic elements and ARIA attributes creates a DOM that assistive technologies can interpret meaningfully, while poorly structured markup or content rendered through images, Flash, or canvas elements creates "black boxes" in the DOM that are inaccessible. The accessibility tree, derived from the DOM, is the specific representation exposed to assistive technologies.