Simple Definition:

Demand is the desire or need of consumers for a particular product or service. It represents the quantity of goods or services that people are willing and able to buy at a certain price. The concept of demand is an important factor in determining the price and availability of products in the market.

For example, if the demand for smartphones is high, it means that many people want to buy smartphones. This can lead to an increase in the price of smartphones or the introduction of new models to fulfill the demand.

Very Simple Definition:

Demand is what people want to buy. It is how much of something people are willing to buy at a certain price.

For example, if many people want to buy smartphones, it means there is a high demand for smartphones.