Living organisms on earth depend on each other in many ways. Ecosystems have many different organisms that live together and rely on their environment to survive.
Producers are organisms that harvest energy from nutrients on earth in order to make food. Producers provide the energy that is used for all other non-producer organisms on earth.
Example: A carrot plant is a producer because it uses nutrients from the soil in order to create energy in the form of food.
Consumers are organisms that eat plants and animals in order to get energy.
Example: A rabbit eats carrots in order to have energy.
Decomposers are organisms that break food energy down into nutrients that can be consumed by producer organisms.
Example: Worms can decompose dead rabbits into nutrients that plants can use.
Organisms living in an ecosystem are interdependent because they need one another in order to survive.
Source: Biology Concepts & Connections Fifth Edition Neil A. Campbell, et all.