The technique of the present invention intermediates between an arbitrary client and an arbitrary printer connecting with a network to actualize practical printing works. A print portal system utilizing a server connected to the network intermediates between the client and the printer to execute a printing operation. The client outputs a printing requirement, which specifies print data of interest and a printer as an output resource, to the print portal system. The print portal system converts the input print data into data of a general purpose format, which does not depend upon the type of the printer, and transfers the converted print data to the specified printer.