Definition - What does Food Chain mean?
Food chains or food webs refer to a system through which energy is passed from one species to another beginning with producer organisms that are able to use sunlight energy to create foods. These are in turn consumed by herbivores, which then become prey species for apex predators. The final link in the chain is the detritivores that consume dead organic matter, breaking it down into elements that can once again be used by producer organisms.
Safeopedia explains Food Chain
Food chains illustrate the interdependence of species in an ecosystem. If any element within a food chain is eliminated or disrupted, the entire food chain is disrupted. For example, a reduction in predators will cause an increase in herbivores who can then overgraze producer species. Once this occurs, the herbivores begin to starve, and the entire food chain collapses.