The platters are made of concentric tracks, the outer track can hold more data than the inner track, are longer in size than inner track.

Zone bit recording utilizes the disk efficiently.

This mechanism groups tracks in to zones based on their distance from the center of the disk.

The zones are numbered with the outermost zone being zone 0.

An appropriate no of sectors per track are assigned to each zone, so a zone near the center of the platter has fewer sector per track than a zone on the outer edge.