Air cargo, commonly known as air freight, is collected by firms from shippers and delivered to customers. Aircraft were first used for carrying mail as cargo in 1911. Eventually manufacturers started designing aircraft for other types of freight as well.
A consumer is  a person or organization that uses economic services or commodities. In economic systems consumers are utilities expressed in the decision to trade or not.
A quaternary consumer is an animal that is at the top of the food chain. These animals mainly eat or prey on animals below them on the food chain, such as tertiary and secondary... A quaternary consumer is an animal that is at the top of the food chain.