Every society must answer three economic questions: what to produce, how to produce it, and who gets what is produced. There are four main economic systems - traditional, command, market, and mixed - that provide different answers to these questions. A traditional system answers based on long-standing customs, a command system uses central planning, a market system relies on supply and demand, and a mixed system blends multiple approaches. Each system has advantages and disadvantages related to factors like innovation, individual freedom, and provision of public goods. Most modern societies utilize a mixed system with some degree of government intervention in the market.