The two most common type of food chain is-
1. Detritus food chain- It begins with dead organic matter, passes to microorganisms and then passes to organisms that feed on detrivores and predators. This type of food chain is observed in temperate forests.
2. Grazing food chain- This food chain begins from the green plants that passes on to the herbivores, then primary consumers and end at carnivorous animals. It is a most important food chain observed in nature.