Magneto-optic disks, also known as MO disks, are a type of rewritable optical storage media that use a combination of magnetic and optical technology for data storage. MO disks were widely used in the 1990s and early 2000s for backup and archival purposes, particularly in the medical and government sectors. While their popularity has waned with the advent of more advanced storage technologies, MO disks remain a viable option for certain applications. Synonyms for magneto-optic disks include MO disks, magneto-optical disks, and magneto-optical storage. Other related terms include optical disks, rewritable disks, and data storage media.