Here's why:

* Autotrophs are organisms that can produce their own food from inorganic sources, such as sunlight, carbon dioxide, and water. They don't need to consume other organisms to get energy.

* Heterotrophs, on the other hand, are organisms that obtain their food by consuming other organisms.

Some examples of autotrophs include plants, algae, and some bacteria. They use processes like photosynthesis to convert sunlight into energy.