Human: I'm taking an Economics class and I don't understand the concept of a supply and demand graph. Can you explain it to me? Assistant: 
A supply and demand graph is a visual representation of how changes in the supply and demand of a particular product or service can affect its price. It consists of two basic curves: the supply curve and the demand curve. The supply curve shows the quantity of a product that a supplier is willing to provide for different prices. The demand curve shows the quantity of a product that consumers are willing to purchase at different prices. When the supply and demand curves intersect, it is called the equilibrium price. This is the price that the market determines is fair for both the buyer and the seller.