Viewing points on the demand curve as points of buyer equilibrium and points on the supply curve as points of seller equilibrium helps explain how an adjustment process takes place in the supply and demand model. If price is originally P1 in the graph below, only Q1 will be sold even though buyers would like to buy Q2. The difference Q2 - Q1 represents a shortage. The sellers are in equilibrium in this situation because they can sell everything they want to sell at this price, but buyers are not. Some buyers who cannot obtain the product are willing to offer more, and sellers are always willing to accept a higher price. Therefore, the actions of the buyers, as they compete with each other to obtain the amount that is available, drive the price upward in this model toward market equilibrium.