This document discusses key concepts related to demand, including that demand is the amount of a good consumers are willing and able to buy at a given price. It also covers the law of demand, which states that as price increases, quantity demanded decreases, and vice versa. Additionally, it explains the concepts of income and substitution effects, marginal utility, and diminishing marginal utility in relation to demand. An example demand schedule for a TV at different future price points is also provided.