Most Web page designers use a table-based layout to achieve a coherent and consistent look. There's a different way to achieve the same look. Using CSS and DIV tags reduces markup code, speeds up page downloads, separates content from its visual presentation, and brings your code closer to Web standards compliance--all while making your website more appealing to search engine spiders. Alejandro Gervasio explains how it's done, with copious examples.
As stated above, with minor modifications to the code, we can easily add another column to our existing layout, keeping widths and heights expressed in pixels. These simple examples show clearly that once we have defined our general layout, we are able to add more DIVS into the main containers or other elements, building more complex layouts with little or no effort. In a moment, we’ll see another interesting approach for styling DIVS: floating boxes.
Style Sheets 
/ 641 
HTML5 Boilerplate Introduction
