Nutritional yeast is specifically grown to be used in food.
It's a great source of protein and B vitamins which makes it popular in vegan cooking. It is often added in place of cheese or to thicken a sauce. It has a savoury flavour.
Nutrition yeast is usually found in the heath food or spice section in the supermarket. It is sold as a powder or flakes.
It is fat free, sugar free, gluten free and vegan.