Trophic levels make up the food chain. All food chains and webs have at least two or three trophic levels. Normally, the maximum trophic levels are four.
The levels are:
1: Plants and algae (producers).
2: Herbivores (primary consumers).
3: Carnivores (secondary consumers).
4: Carnivores that eat other carnivores (tertiary consumers).
However, many consumers also feed at more than one trophic level.