The document discusses criteria for classifying phases of economic development, including means of livelihood, extent of economic activity, and medium of exchange. It provides examples of how people obtained food through hunting and fishing in early phases, transitioned to farming and ownership of land, and now rely on manufacturing companies using machinery. Economic activity expanded from satisfying needs within families to relations between families and grouping of villages. Exchange evolved from direct bartering of goods and services to using stable objects as money and eventually incorporating credit through promises of future payment.