Source : Free On-Line Dictionary of Computing

constant angular velocity
     
         (CAV) A {disk} driving scheme in which the {angular
        velocity} of the disk is kept constant.  This means that the
        {linear velocity} of the disk be larger when the reading or
        writing the outer tracks.  The disadvantage of this technique
        is that the read/write speed varies from track to track.
        However, as mechanical stability puts an upper limit on the
        angular velocity (and not the linear velocity) this allows the
        full potential of the drive is used.
     
        (1998-03-27)