DOM

In 1993, when the first graphical web browser displayed a simple HTML document, the rendering process was straightforward: parse markup, apply basic styles, display text. Today’s browsers execute a far more complex sequence involving multiple intermediate representations, GPU acceleration, and sophisticated optimization strategies. Understanding this pipeline explains why some pages render in under 100 milliseconds while others struggle to maintain 60 frames per second during animations. The browser rendering pipeline consists of five primary stages: constructing the Document Object Model (DOM), building the CSS Object Model (CSSOM), creating the render tree, calculating layout, and painting pixels to the screen. Each stage transforms data from one representation to another, and bottlenecks in any stage cascade through the entire process. ...