What is Layout, Paint, Composite? and How Do They Affect Web Performance?

Layout, Paint, and Composite are key stages in the browser's rendering pipeline. The process begins with HTML and CSS, leading to the creation of a Render Tree. Layout determines the position and size of each element on the page. Changing layout-related CSS properties, like margins or width, triggers a Reflow. Paint involves filling in pixels for elements, such as background colors or borders. If paint properties change, it results in a Repaint. Composite promotes elements to layers and utilizes the GPU for transformations and opacity changes. These layers are then combined to display the final webpage. Triggering Layout or Paint is more computationally expensive than Composite-only operations. Optimizing CSS to trigger only Composite steps significantly improves web performance.