7Phase 7 of 12
DOM construction
The HTML parser's output: a tree of nodes that scripts and styles both target.
Animation loop, let it play, or use the controls.
The DOM is the live, in-memory representation of the document. Every element, every attribute, every text node has a corresponding object. The browser's layout, paint, accessibility tree, devtools inspector, scripts and styles all read from this same tree.
DOM construction can be expensive when it grows large, tens of thousands of nodes start to noticeably slow style recalculation and layout. Frameworks like React abstract over it, but the underlying tree is still what the browser cares about.
Takeaway
The DOM is the canonical model of the page. Everything else, render tree, accessibility tree, scripts, derives from it.