New Zealand web firm provides enough detail to be truly useful, with proper explanations that really describe the meaning.
The Motive Web Design Glossary
above-the-fold
The portion of a webpage visible in the browser window when the page first loads is decribed as being ‘above-the-fold’. The phrase is a reference to the area of a newspaper visible when folded for display in a news stand, typically containing the masthead and lead story.
A more appropriate (medium-appropriate) equivalent being “before-the-scroll”.
The concept of a fold was seen as key in the early days of the web, based on the belief that only content placed in this area of the page—usually the first 300 vertical pixels—could be guaranteed “eyeballs”. Over time, users have become more accustomed to scrolling, however the first fold continues to be highly sought-after by advertisers.