Magneto-optical ("MO") disk drives are versatile removable storage devices, which use very robust and inexpensive media. You can use an MO disk just like a large floppy disk, or like a hard disk. The How MO Drives Work section explains how data is written to and read from MO disks.

Sony's increasing popular "MiniDisc" system uses a type of magneto-optical disk.

There are many advantages in using MO disks instead of other types of media.

MO drives are available as internal or external, SCSI or IDE/ATAPI drives. MO "jukeboxes" are also available, but these are intended for business use as they are expensive, and few Amiga users need to store hundreds of gigabytes of data. Also, special driver software would be required and none exists for the Amiga.