Supply is the amount of one good or service in that market. A market driven economy could utilize supply to regulate price. Generally, if the supply is higher than the demand for that good the price will be lower. If the supply is lower than the demand, the price will tend to increase.
This is a 3 year model that depicts the flows between Price, Supply and Demand in the real-estate market.
Throughout the model viewers can observe how the figures Price, Supply and Demand alter each other in an increasing or decreasing way.
Price is decreased by the growing supply of HousesForSale and increased by the growing demand of people wanting to buy. As Price decreases, HousesForSale increases and Price decreases as HousesForSale increase.