A service is a transaction in which no physical goods are transferred from the seller to the buyer. The benefits of such a service are held to be demonstrated by the buyer's willingness to make the exchange. Public services are those that society (nation state, fiscal union, region) as a whole pays for. Using resources, skill, ingenuity, and experience, service providers benefit service consumers.
Service-relevant resources, processes and systems are assigned for service delivery during a specific period in time. If the service consumer does not request and consume the service during this period, the related resources may go unused. From the perspective of the service provider, this is a lost business opportunity if no other use for those resources is available.
The service provider must deliver the service at the time of service consumption. The service is not manifested in a physical object that is independent of the provider. The service consumer is also inseparable from service delivery. Examples: The service consumer must sit in the hairdresser's chair, or in the airplane seat. Correspondingly, the hairdresser or the pilot must be in the shop or plane, respectively, to deliver the service.