Tutoring biology, you come across the concept of trophic level. The tutor defines it.

In an ecosystem, a tropic level can be thought of as a level of energy or of consumption.

The organisms at trophic level 1 are called primary producers. By photosynthesis, they harvest energy from the sun to produce carbohydrates. Grass is a primary producer; in the ocean, phytoplankton is an example.

At trophic level 2 are the plant-eaters.

At trophic level 3 are predators (carnivores).

Source:

Mader, Sylvia S. Inquiry into Life, 9th ed. Toronto: McGraw-Hill, 2000.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.