Which technology is used in compact disk to store data

Compact Disks (CDs) use laser technology to store and read data. A CD is made of polycarbonate plastic with a reflective layer that contains microscopic pits. A laser beam scans the surface; and depending on whether it hits a pit or a flat area; light is reflected back differently. This reflection is interpreted as digital information. The technology revolutionized music; software; and data storage in the late 20th century and remains a fundamental concept in optical storage devices.