The floppy disk is a data storage and transfer medium that was ubiquitous from the mid-1970s well into the 2000s.[1] Besides the 3½-inch and 5¼-inch formats used in IBM PC compatible systems, or the 8-inch format that preceded them, many proprietary floppy disk formats were developed, either using a different disk design or special layout and encoding methods for the data held on the disk.