CompactFlash (CF) is a mass storage device format used in portable electronic devices. The format was first specified and produced by SanDisk in 1994. It is now used for a variety of devices; most contain flash memory but some, such as the Microdrive, contain a hard disk.
CompactFlash became the most successful of the early memory card formats, surpassing Miniature Card, SmartMedia, and PC Card Type I in popularity. Subsequent formats, such as MMC/SD, various Memory Stick formats, and xD-Pict