This section introduced the Law of Demand and Law of Supply, Demand and Supply curves, schedules and equations. Desired quantity demanded will be inversely or negatively related to price, and desired quantity supplied will be directly or positively related to price, so long as other factors that affect demand and supply remain unchanged.
Taken alone, the demand or supply relationship don't tell us too much that is interesting. However, as we will see in the next section, when we put demand and supply together we can say quite a bit about how markets work. We will learn what it means for a market to be in equilibrium, what happens when a market is out of equilibrium, and what happens when attempts are made to force a market away from equilibrium.