Above The Fold is the section of a web page that is visible without having to scroll the page down. Above The Fold is normally a term used in banner advertising.

The fold will vary depending on the monitor resolution settings of the visitor to a web site. The lower the resolution setting the higher the fold is on the web page the visitor is seeing.

You as the advertiser should try to get your banner displayed as high on the page as you can, this normally will get your ad viewed more and clicked on more often.