Demand

Demand is an economic measure, which expresses a desire, as well as the ability to pay for goods and services. In and of itself, demand is neither a physical need nor emotional desire. Rather, demand can be understood as willingness to trade things of value, such as goods, money, and labor, for variable amounts of goods and services. The degree to which the demand of goods and services varies is determined by the price asked. Thus, for example, aggregate demand is the figure which represents a total amount of goods and services demanded by the economy at a given market price. Supply is another important parameter with which demand interacts. Economists use demand curve to calculate and express demand graphically.