With the internet being the main source of media and news for millennials it's likely that many do not buy or read printed Newspapers. Therefore, the term 'Above the fold content' may seem alien to many entering the world of marketing.
Above the fold and below the fold originates from when newspapers were the most common form of media. Newspapers are typically folded in half for transport and display purposes.
The title and headlines would be above the fold and their primary purpose was to grab you attention so you buy the paper and unfold it to read on. This is the same as your website only there are no folds. When you click on the link everything visible should be compelling enough to encourage you to scroll down and view everything 'below the fold'.
You will see this terminology used in reporting software which monitors how quickly a website produces the content above the fold prior to the content below the fold. This speeds up the time your website appears to load for your visitors.
Also, with heat mapping software, they look at where the site would typically fold, or in other words where the bottom of the page would be on first load depending on the display size. This helps us know how much of the content people are viewing before they make a decision to stay on the website or not.