Very elementary question, which I could not find in the archives. I note that many sites have a wrapper div within which the whole page sits, while others do not. I would have thought that there is an "implicit" page upon which all the content resides, and that the wrapper is redundant, but the fact that it is used by many (but far from all) sites suggests that there must be some reason for it. (It just adds another layer of nesting of divs, presumably a bit more processing) Advice re. benefit/necessity?