DEMAND: In a specific period, an individual, family, or firm, how much goods/services want to get, when it is supported by ability to perches and will willingness to expand then it is called demand. Demand in economics is how many goods and services are bought at various prices during a certain period of time. Demand is the consumer's need or desire to own the product or experience the service. It's constrained by the willingness and ability of the consumer to pay for the good or service at the price offered. In economics, demand is the quantity of goods or services that consumers are able and willing to buy at a given price at a particular time. Economists use the term demand to refer to the amount of some good or service consumers are willing and able to purchase at each price. Demand is based on needs and wants—a consumer may be able to differentiate between a need and a want, but from an economist’s perspective they are the same thing. Demand is also based on ability to pay. If you cannot pay, you have no effective demand.