Making comparisons between pet food products can be a bit bewildering, and requires an understanding of how to read the label's Nutritional Statement, List of Ingredients and Guaranteed Analysis.
The Canadian Veterinary Medical Association (CVMA) and the American Association of Feed Control Officials (AAFCO) have developed standards for pet food nutrition, so products labelled premium or complete and balanced mean the products comply with those standards.
The CVMA has a testing and certification program, but it is voluntary. Some pet food manufacturers label their product as meeting the AAFCO standards, but it does not imply endorsement of the product by that organization.
Nutritional statements also refer to the suitability of the cat food for all life stages'.
Products for all life stages actually have to meet the needs of all stages, so they have higher nutritional makeup to meet the needs of pregnancy, and high-energy or working dogs. This diet may not be necessary for the normal adult cat or dog, but it is not likely to be harmful.