Utility
the satisfaction received from consumption
Total utility
the total satisfaction received from consumption
Marginal utility
the utility derived from the consumption of one more unit of the good or service
Diminishing marginal utility
the fall in marginal utility as consumption increases
Equimarginal principle
consumers maximise their utility where their marginal valuation for each product consumed is the same, i.e. MUa/Pa = MUb/Pb = … = MUn/Pn.