It refers to the concept of viewing a web page without the help of scrolls.

The resolution settings can vary a great deal from one monitor to another. The fold varies too varies accordingly. If the settings are on higher side then the folds will extend downwards and vice versa. Depending upon the minimum resolution required, fold decisions are often made. Advertisers generally prefer placements higher on a page as they can attract visitors to their ads and force them to click on them. Banner exchanges are of two types. While few such exchanges are direct; swapping the impressions of above the fold, others are not direct. If the banner is supported by an overloaded server, chances are that fold may be rendered less favorable.