This document introduces basic economics concepts including scarcity, opportunity cost, and production possibilities curves (PPC). It defines economics as the study of how limited resources are used to meet unlimited wants. The key assumptions for drawing a PPC are full efficiency and a fixed amount of resources. A PPC shows the various combinations of two goods that can be produced, and is typically drawn as a downward sloping concave curve, reflecting the concept of scarcity where more of one good requires less of the other.