Phase-change memory (PCM) is a fast, low-power, random-access, nonvolatile and potentially low-cost memory technology. PCM chips are the first to be based on phase-change chalcogenide alloys, similar to the film used to store information on compact disc-rewritable (CD-RW) and DVD-RAM optical discs. The technology is also known by other names, including PCRAM and PRAM.