A good is (nonrival or nonexclusive), if for any given level of production, the marginal cost of providing it to an additional customer is (positive, zero, negative). A good is (nonrival or non exclusive) if people cannot be prohibited from consuming it even if they refuse to pay for it.

Nonrival or nonsclusive refers to the production of a good or service from one more customer, while (nonrival or nonexlucsive) refers to exchange, where the cost of charging consuming is prohibitive