Demand refers to the desire and ability of consumers to purchase goods or services at a given price. It reflects how much of a product people want and can afford, influencing market prices and availability. Higher demand often leads to increased production and can drive prices up, while lower demand may result in reduced production and lower prices. In economics, demand is often represented by a demand curve, which shows the relationship between price and quantity demanded. Factors affecting demand include consumer preferences, income levels, and the prices of related goods, such as substitutes or complements. Understanding demand is crucial for businesses and policymakers to make informed decisions.