Hackers and painters aren't so different, Paul Graham would say. And much like art, software engineering has gone through movements as well.
Web 1.0 (1996~2004) was about static and synchronous content. The Document Object Model (DOM) and its predecessors allowed developers to treat a webpage as a tree and modify it.
The evolution of the DOM. The webpage isn't modifying directly through the DOM anymore, but rather a virtual DOM, that allows developers to declaratively, rather than imperatively, describe the page. Some applications like Google Sheets and Figma write directly to the browser canvas, "drawing" applications that don't fit cleanly in a tree object model.