Above the Fold:The term "above the fold" originally related to newspaper publishing, since stories above the fold of the paper were usually the most read and most important. In web design, it refers to the portion of a web page that can be viewed in a standard web browser window without scrolling.
77% of website visitors don't scroll down, according to a 2006 study by Jacob Neilsen. This means that online advertising often focuses on the area of the website that's considered above the hold. Many web advertising firms will even require that their ads are placed in that area, even specifying a specific range of pixels. Ads placed above the fold often perform better and cost more for advertisers to place.
Since screen sizes and resolutions very dramatically from device to device, there's no set measurement for what is considered above the fold. Many websites have adapted using responsive web design, which allows their site to resize to fit a user's unique browser.
Above the fold may also refer to search result pages. Many websites use SEO tactics to appear higher in search rankings so they appear on the first page or in the first few results, making it more likely for web users to click on them.