The Box Model

3 main types of elements : Block, Inline, List.

"div" element : generic Block : to put together a set of Block

"span" element : generic Inline : to identifiy some part of a text

The Block and List type follow this Box Model

http://www.w3.org/TR/CSS21/box.html#box-dimensions

Source : http://www.w3.org/Style/Examples/011/firstcss