This document provides an introduction to applied economics. It defines economics as the study of how societies use scarce resources to produce and distribute goods and services. It discusses that economics deals with scarcity, choice, and opportunity cost. The key economic resources are land, labor, and capital. It also outlines the basic economic problems societies face in determining what and how much to produce, how to produce, and for whom to produce. Finally, it briefly describes the main economic systems of traditional economies, command economies, and market economies.