Primary producers are plants. Primary consumers are herbivores and secondary consumers are carnivores.
1.Primary producers use energy from the sun to make their own food in the form of glucose
Then primary producers are eaten by primary consumers who are then eaten by secondary consumers who are then eaten by tertiary consumers and so on.
As this cycle continues, energy flows from one trophic level to the next, and each time the organism only receives 10% of the energy from the previous organism.