Marginal Utility is a basic concept of economics. Marginal Utility the utility of the marginal use of a product or service. It is the utility of the specific use to which the agent would put a given increase in the production of that good or service.
It is the quantified change in utility which is obtained by using one or more or one less unit of that good or service. This term was first used by the Austrian Economist Friedrich Von Wieser