floppy disk

In computing, a storage device consisting of a light, flexible disk enclosed in a cardboard or plastic jacket. The disk is placed in a disk drive, where it rotates at high speed. Data are recorded magnetically on one or both surfaces.

Floppy disks were invented by IBM in 1971 as a means of loading programs into a computer. They were originally 20 cm/8 in in diameter and typically held about 240 kilobytes of data. Present-day floppy disks, widely used on microcomputers, are 8.8 cm/3.5 in in diameter, and generally hold up to 2 megabytes, depending on the disk formatting.

Floppy disks are inexpensive, and light enough to send through the post, but have slower access speeds and are more fragile than hard disks. The use of floppy disks is increasingly being replaced by the higher capacity and more robust memory stick or pen-drive. (See also disk.)