How the data in CD-RW can get erased?
In a CD-RW phase changing metal alloy film is present in between the polycarbonate substrate layer and metal reflective layer. Data is written to the disc by heating the film above the melting temperature. By heating the phase-changing film to a specific temperature above the crystalline temperature but below the melting temperature, the film can revert back to the crystalline state, thereby erasing previous bits. The writing and erasing processes can be done together in a single pass when rewriting a disc.
