Decomposers are organisms that eat dead or decaying organisms. They carry out the natural process of decomposition. Fungi is the primary and most common of decomposers.

Primary consumers are animals that get their food from eating plants. These are known as herbivores. A deer is the primary and most common primary consumer.

Secondary consumers get their energy from the other animals they eat. They eat animals that are primary consumers. A lion is the primary and most common secondary consumer.

Organisms make their own food such as plants. Grass is the food that primary consumers [herbivores] eat. Grass is the primary and most common producer.

Animals that eat only plants. A giraffe is the most common herbivore.

Animals that eat only other animals or [meat]. For example, a lion is the most common carnivore.

Animals or humans that eat both animals and plants. For example us humans are omnivores.

A food chain shows the flow of energy from one organism to another to yet another. But the relationships in an ecosystem are more complex.