In a compatible recording and reproducing apparatus which is capable of recording and reproducing information on both a video disk and a digital audio disk, a relative angle between an optical axis of a laser beam emitted from a pickup and the disk is adjusted so as to be suitable for the disk loaded on the apparatus. Further, the movement of the pickup in the radial direction of the disk is regulated in accordance with the difference in the outer diameter of the two kinds of disks. A problem due to the difference of the track pitch in the two kinds of disks is solved by moving the pickup in a direction perpendicular to a radial direction of the disk. In addition, an objective lens for focusing the laser beam on the disk is selected within a predetermined range of an effective numerical aperture in order to simplify an optical system of the apparatus.