| Term | Definition |
| elasticity | a measure of the responsiveness of the quantity demanded or quantity supplied to one of its determinants |
| price elasticity of demand | a measure of how much the quantity demanded of a good responds to a change in the price of that good |
| elastic | when the quantity demanded or supplied responds substatially to a change in one of it determinants |
| inelastic | when the quantity demanded or supplied responds only slighlty to a change in one of its determinants |
| total revenue | the amount paid by buyers and received by sellers of a good computed as P x Q |