There are three types of economic exchange in ancient societies:
reciprocity, redistribution, and market exchange.
the oldest is reciprocity.
reciprocity is the exchange of one good or service for one of the same value.
redistribution involves collecting goods and then redistributing them as those in charge of the society decides is best for the society.
the market exchange economy involves buying and selling goods and services with actual money.
the price of items and services are determined by supply and demand.