It's a corn that can vary in color from white to yellow to purple. The Peruvians use it in all sorts of dishes (stir-fries, soups, stews, etc) and snacks (like tamales and humitas, etc). They even use it to make beverages like chicha morado which is a purple non-alcoholic beverage that kind of reminds me of a very sweet version of Cool-Aid (except that it's not grape flavored). I think they also make a beer with it.