A library of a PC is easily synchronized with recorded contents of a disc loaded into a recording and reproducing apparatus (PD). The PC has a dynamic group and a database. Contents of the dynamic group are, dynamically changed. The dynamic group is correlated with the ID of the disc on which the contents of the dynamic group have been recorded. When the CP and the PD are connected, the ID of the disc loaded into the PD is read. The database is referenced for the ID of the disc. When there is a corresponding dynamic group, the dynamic group is compared with the recorded contents of the disc. Contents that exist in the dynamic group and that do not exist on the disc are checked out to the disc. In contrast, contents that exist on the disc and that do not exist in the dynamic group are checked in to the PC. In addition, the reproduction order of contents of the dynamic group is reflected to contents of the disc. The user can synchronize the recorded contents of the disc with the library of the PC only by connecting the PC and the PD.