A common carrier is an organization that transports people, goods, or services and offers its services to the general public under license or authority provided by a regulatory body. A common carrier holds itself out to provide service to the general public without discrimination for the "public convenience and necessity". A common carrier must further demonstrate to the regulator that it is "fit, willing and able" to provide those services for which it is granted authority. Common carriers typically transport persons or goods according to defined and published routes, time schedules and rate tables upon the approval of regulators. Public Airlines, railroads, bus lines, cruise ships, motor carriers (i.e., trucking companies) and other freight companies generally operate as common carriers.