A feeding hierarchy in which organisms in an ecosystem are grouped into trophic (nutritional) levels and are shown in a succession to represent the flow of food energy and the feeding relationships between them.
The directional flow of materials and energy from one organism to another is graphically represented by arrows. For example: trees and shrubs (producer) → giraffe (herbivore) → lion (carnivore).
Most food chains have only about four to five links since too many links in a food chain will result in high demand, less supply of food (and therefore energy).
See also: food web, trophic level.