Superfoods are nutrient-dense foods that provide high levels of antioxidants and essential nutrients while being low in calories. Green superfoods, seafood, and herbs are highlighted for their health benefits, including detoxification, weight loss, and immune support. The document discusses various superfoods like nettle, aloe vera, echinacea, and common foods like blueberries and avocados that contribute to overall health and well-being.