Markets bring together buyers and sellers to establish an equilibrium price for a good or service. Demand is the willingness to buy a product at a given price, depicted by a downward sloping demand curve. Supply is the willingness of producers to provide a product at a given price, depicted by an upward sloping supply curve. The equilibrium price is where the supply and demand curves intersect and the quantity demanded equals the quantity supplied. Price ceilings set a maximum price and can cause shortages. Price floors set a minimum price and can cause surpluses.