Floppy disk drive
A floppy disk is a data storage medium that is composed of a disk of thin, flexible ("floppy") magnetic storage medium encased in a square or rectangular plastic shell. Floppy disks are read and written by a floppy disk drive or FDD, the initials of which should not be confused with "fixed disk drive", which is another term for a hard disk drive. Invented by IBM, floppy disks in 8", 5.25", and the newest and most common 3.5" formats enjoyed many years as a popular and ubiquitous form of data storage and exchange, from the middle 1970s to the late 1990s. However, they have now been largely superseded by flash and optical storage devices while e-mail has become the preferred method of exchanging small to medium size digital files.