A CD Read/Write (CD/RAW) disk is very similar to a WORM disk with the exception that we can erase its previous content and write on it multiple times. Such disks use metallic alloy layer. Laser beam changes the chemical property during writing (or burn process), changing reflectivity at desired places. The land-pit difference on CD-RW is not significant and hence CD drives have to be compactible to read such disks. A CD-RW disk usually has a lifetime of 100 or more erase-write cycle. CD-RW drives have the capability to change the chemical property again of the metallic alloy layer when we erase old data and write new data on a CD-RW disk. CD-RW disks are little expensive than CD-R disks, but offer great cost-saving because of their erase and rewrite capability.