Economics; The study of how people use limited resources to satisfy unlimited wants. Scarcity; The basic problem: resources are limited, but wants are unlimited. Choice; Deciding how to use resources. Opportunity Cost; The next best thing you give up when making a choice. Land; Natural resources (water, soil, minerals). Labor; Human effort, work, and skills. Capital; Tools, machines, and buildings used to produce goods. Entrepreneur; A person who starts a business by combining land, labor, and capital. Money; A medium of exchange with value, used to buy goods and services. Barter; Trading goods/services directly without money. Trade; Exchanging goods, services, or money. Market; Any place where buyers and sellers meet to exchange. Goods; Physical objects people buy (shoes, food, cars). Services; Actions people do for others (teaching, cleaning, driving). Consumer; A person who buys goods and services. Producer; A person or business that makes goods or provides services. Demand; How much people want a good or service. Law of Demand; When prices go up, people buy less; when prices go down, people buy more. Supply; How much of a good or service producers are willing to sell. Law of Supply; When prices go up, producers make more; when prices go down, they make less. Equilibrium; The price where supply and demand meet. Profit; Money left after costs are paid. Cost; The money needed to make or buy something. Revenue; Total money a business earns from selling. Competition; When businesses try to attract customers by offering better prices or products. Market Economy; An economy where decisions are made by individuals and businesses. Command Economy; An economy where the government makes most decisions. Mixed Economy; A system combining free markets and government control. Taxes; Money people pay to the government. Public Goods; Goods/services provided by the government for everyone (roads, schools, defense).