Food chains:
A food chain is a diagram that shows how energy in food flows from one organism to another. Its also thepathway of energy transfer through various stages as a result of the feeding patterns of a series of organisms.
Food webs:
A food web is a diagram that shows the feeding relationships between organisms in an eosystem. An arrow goes from the prey to the predator. There are two main food webs on Earth: a land food web and an aquatic food wed.
Energy Pyramid:
Shows an ecosystems loss of energy. Less energy is available at higher levels because only energy stored in the tissues of an organism can be transferred to the next level.