The interpretation by the browser’s rendering engine is where your headaches begin. The W3C has gone to great lengths to create specifications by which browser developers should render the Web code. Nonetheless, bugs, omissions, and misinterpretations still creep in, meaning that no two browsers will render a Web page in exactly the same way. For the most part, these differences go unnoticed by most users, but occasionally the differences are glaring and require that you do some extra work to get the page to look right with the broadest spectrum of browsers.