Plants (with any of the photosynthetic pigments) are the only producers in the world. Because, they are the only things which can make their own food. All other organisms (including some plants - fungi!) are the consumers (may primary consumer, secondary consumer, tertiary consumer...). The primary consumers are usually the herbivores (e.g. goat, cow, horse, etc.). The secondary consumers are primary carnivores (e.g. fox, snake, hyena, etc.). The tertiary consumers are secondary carnivores (cheetah, tiger, lion, etc.).Photosynthetic plants are the only producers that can produce food by using water and minerals from soil, carbon dioxide from air, and energy from sunlight in the presence of chlorophyll and other photosynthetic pigments in the photosynthetic regions such as leaves and young greeny tender stems.All other living things (including human beings) depend on plants directly or indirectly for their food! So, they are call non-producers or consumers.