In a communication system for serving data corresponding to a request from the user and charging the user for the data served to the user, when the user designates a result of a desired one of a plurality of different operations, a usage management unit selects a one, corresponding to the user's designation, of a plurality of processors which effect operations corresponding to a plurality of different algorithms, respectively. When the processor corresponding to the designation is selected, an algorithm processor makes an operation corresponding to the designation. A management center charges the user for the use of the algorithm.