This document discusses the concepts of individual demand, market demand, and the assumptions of the law of demand. It provides examples of an individual demand schedule and curve for an individual named Adam. It then explains that market demand is the aggregate of individual demands. A market demand curve is created by horizontally summing individual demand curves. The market demand function is the horizontal summation of individual demand functions. Finally, it provides an example of how individual demand curves from three individuals (A, B, and C) can be summed to create a market demand curve.