Like the law of demand, the law of supply demonstrates the quantities that will be sold at a certain price. But unlike the law of demand, the supply relationship shows an upward slope. This means that the higher the price, the higher the quantity supplied. Producers supply more at a higher price because selling a higher quantity at a higher price increases revenue.
A, B and C are points on the supply curve. Each point on the curve reflects a
direct correlation between quantity supplied (Q) and price (P). At point B, the
quantity supplied will be Q2 and the price will be P2, and so on. (To learn how
economic factors are used in currency trading, read Forex Walkthrough: Economics.)