Because users wish, but also developers as a site to be more interactive and have as many dynamic graphics, new technologies have been implemented markup and styling.
Thus by implementing two technologies can create various graphical effects without the need for image processing in Photoshop, Corel and can play for example audio, video which until now were only possible using Flash.
CreateWebSite combine these technologies in moderately due to their lack of compatibility with older versions of browsers and especially with Internet Explorer, but focuses on their use wherever possible without greatly affecting the browsers compatibility.