Heterotrophs are organisms that cannot produce their own food and must obtain energy by consuming other living things. This group includes animals, fungi, and many bacteria. They rely on organic compounds from plants or other animals to meet their nutritional needs. Unlike autotrophs, which create their own food through processes like photosynthesis, heterotrophs play a crucial role in ecosystems by breaking down organic matter. They help recycle nutrients and maintain the balance of food webs, making them essential for the health of their environments.