Law of demand is a fundamental economic principle postulating an inverse relationship between the price of a good or service and the quantity of that good or service demanded by consumers, assuming all other factors remain constant (ceteris paribus). This concept investigates consumer behavior in response to price fluctuations, explaining how changes in price influence the quantity of a product or service consumers are willing and able to purchase in a market. Its key characteristics include the empirical observation of a downward-sloping demand curve and its reliance on the ceteris paribus condition to isolate the effect of price. Significance lies in its foundational role within microeconomic theory, serving as a critical tool for analyzing market dynamics, predicting consumer responses, and informing pricing strategies and economic policy.