Substitutes:Substitutes are goods or services that can be used in place of one another, where the demand for one decreases as the demand for the other increases. They have a negative cross-price elasticity of demand.
Cross-Price Elasticity of Demand:The measure of how responsive the demand for one good is to a change in the price of another good. Complements have a positive cross-price elasticity, while substitutes have a negative cross-price elasticity.
Equilibrium Price and Quantity: The price and quantity at which the supply and demand for a good or service intersect, representing the market clearing point.