diskette

An inexpensive, low-capacity storage medium, usually measuring 3.5 inches in diameter, often referred to as a floppy disk.

In computer technology, a small disk of flexible plastic, coated with a magnetizable material and enclosed in a protective jacket, used to store digital data. Note: A diskette is distinguished from a hard disk by virtue of the fact that it is flexible, and unlike most hard disks, is removable from its drive. Synonyms flexible disk, floppy disk.