Like the foods packaged for humans, pet food packaging can be confusing and frustrating to understand. There are regulations in place as to what the manufacturer can state on the packaging. In general, "natural" and "holistic" are descriptions denoting the food is free of chemical preservatives, color additives, etc. Organic foods, on the other hand, must be certified organic by an agency before the manufacturer can call the food "organic". Organic foods are typically more expensive for this reason. These foods are antibiotic-free, hormone-free, pesticide-free when labeled organic. Some foods may have organic ingredients but may not be totally organic. The protein source may not be organic while the carbohydrate ingredients (oats, barley, rice, etc.) are organic. The package label will define this for you.