A floppy disk or floppy diskette (sometimes casually referred to as a floppy or diskette) is a type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a fabric that removes dust particles from the spinning disk. Floppy disks are read from and written to by a floppy disk drive (FDD).
The first floppy disks, invented and made by IBM, had a disk diameter of 8 inches (203.2 mm).Subsequently the 5¼-inch and then the 3½-inch became a ubiquitous form of data storage and transfer into the first years of the 21st century. 3½-inch floppy disks can still be used with an external USB floppy disk drive. USB drives for 5¼-inch, 8-inch, and non-standard floppy disks are rare to non-existent. Some individuals and organizations continue to use older equipment to read or transfer data from floppy disks.