This document discusses key concepts related to demand, including: 1. It defines demand as a desire backed by willingness and ability to purchase, and identifies three essential components of demand - desire, purchasing power, and willingness. 2. It explains demand analysis as determining factors affecting demand, measuring elasticity, forecasting demand, and increasing demand to efficiently allocate resources. 3. The law of demand states that quantity demanded is inversely related to price - as price increases, quantity demanded decreases, and vice versa. 4. Elasticity of demand measures responsiveness of quantity to price changes. There are three types: price, income, and cross elasticity. Price elasticity specifically measures the percentage change in