Inelasticity refers to a situation in economics where the quantity demanded or supplied of a good or service does not change significantly when its price changes. This means that consumers will continue to buy nearly the same amount of a product, even if its price increases or decreases. Common examples of inelastic goods include necessities like food, medicine, and gasoline, where people need these items regardless of price fluctuations. Inelasticity is measured using the price elasticity of demand or supply, which is a ratio that compares the percentage change in quantity to the percentage change in price. If the absolute value of this ratio is less than one, the good is considered inelastic. Understanding inelasticity helps businesses and policymakers make informed decisions about pricing and resource allocation, especially for essential goods and services.