Final answer:
Heterotrophs are organisms that derive their energy and nutrients by consuming other organisms, either dead or alive. They are distinct from autotrophs, which produce their own food from inorganic substances, and decomposers, that consume dead organic matter and help recycling nutrients.
Step-by-step explanation:
Organisms that obtain energy and nutrients by consuming either living or dead organisms are known as heterotrophs. This means that they don't produce their own food, but instead rely on other organisms for nourishment. These include all animals and fungi and many bacteria and protists.
Autotrophs, on the other hand, are organisms that can make their own food from inorganic substances such as sunlight or chemicals. This group comprises plants, algae, and certain types of bacteria.
The third category presented, producers, is actually another term for autotrophs as they produce their own food—essentially creating the base for food chains in ecosystems.
Finally, decomposers are a subset of heterotrophs that specifically consume dead organic matter, aiding in nutrient recycling.
By feeding on other organisms or their remains, heterotrophs play a major part in the circulation and redistribution of energy and matter within ecosystems.
Learn more about Heterotrophs