Heterotrophs are those organisms that must obtain their organic carbon source from an outside organism. For example, we have to obtain our carbohydrates proteins, as well as lipids, from other types of organisms. So that's exactly why we need to eat food products, animal products, as well as plant products to obtain these organic carbon containing things. So humans are examples of heterotrophs. We obtain our carbon source from other organisms. Now, the other side of the spectrum are autotrophs.