Sweet corn is primarily harvested at a young stage, so it's not just the variety of corn, but also the choices of how and when to harvest and process.
A lot of the edible varieties are different cultivars, generally categorized as flint corn or flour corn. Flint corns can be processed into grits and coarser cornmeal, while flour corns can be processed into corn starch and corn flour.
Field corn/dent corn is the majority of what American farmers grow, and is generally not intended for direct human consumption, unless heavily processed into bourbon and corn oil and corn syrup.
Even the stuff that is processed into ethanol (for whiskey to drink or for fuel or other industrial use) is still converted into animal feed and corn oil after the fermentable carbohydrates are extracted.
Oh I don't like that subscription model one bit. What assurance does an owner have that their subscription price won't change over the life of their vehicle?