Erasable optical disk drives ,Like magnetic hard disk, scan overwrite data ,erasable disks are the most flexible type of optical storage media. Some of these optical disks are called magneto-optical disks because the bit patterns are aligned magnetically on the disk. Because the magnetized 1 and 0 bits reflect light differently, the bit patterns are optically read using a laser, hence the name magneto optical.
The hardware cost and slow transfer speed’s currently associated with erasable optical disks have kept them from economically competing with magnetic hard disk. The increased storage capacity of optical disk technology gives it great potential as a popular type of storage hardware. Although research continues to improve erasable optical disk technology magnetic storage media are still the storage workhorses for most computer systems.