above the fold
In a browser window, the content that is immediately visible after a web page loads and before a user scrolls down the page. When designing your layout, use flexible formats to best display the highest priority products, features, sales, notifications, options, etc in this area.
With mobile and tablets, the area of above the fold greatly differs, especially on the size and dimensions of the screen and orientation when viewing (portrait vs landscape). Using responsive themes and testing can help find the right mix of content and layout.