Chapter four for economics primarily focuses on the supply and demand situation within the economy.  Supply and demand goes hand in hand with how the economy turns out to be but they are both dependent on each other. Demand is the amount of product that the consumers have demanded whereas supply is the amount of product that is available by the supplier. Depending on both of these results they yield what the monetary value of products will be. For example if there is more people who want a certain computer than the supplier can give, then the supplier will increase the price because its more desired and demanded. Due to the number of customers that the supplier will lose, the supplier must increase the price to get even or make a certain profit. There are a lot of things that can affect both of these factors of supply and demand. For example, in order for the demand curve to change that would depend on income, number of buyers and external factors that depend on the consumers . For the supply curve to change, most of the factors that change it are internal factors within the firms such as the amount of products available and other firms with the same product within the market. Supply and demand goes hand in hand to make our economy go round.