Answer:
A consumer is an organism that eats other organisms to gain energy; it is also called a heterotroph.
A producer is an organism that makes its own food; it is also called an autotroph.
A decomposer is an organism that breaks down waste and dead organisms.
Explanation:
Green plants are examples of autotrophs that make their own food by photosynthesis - they don't rely on other organisms to provide them with energy.
In contrast, many organisms rely on other organisms as an energy source. These organisms are called consumers or heterotrophs. They consume producers and other consumers.
Decomposers such as some fungi, bacteria, and certain insects break down dead or decaying biological material and recycle the nutrients back into the soil.