Often referred to as a CompactFlash card, a very small removable mass storage device that relies on flash memory technology, a storage technology that does not require a battery to retain data indefinitely. CompactFlash cards can support 3.3V and 5V operation and can switch between the two, in contrast to other small-form factor flash memory cards that can only operate at one voltage. There are two types of CompactFlash cards to accommodate different capacities: Type I cards are 3.3mm thick while Type II cards are 5.5mm thick. The card was designed based on the PCMCIA PC Card standard and can fit into a PCMCIA slot with an adapter.
CompactFlash applications include PDAs, cellular phones, digital cameras and photo printers.
CompactFlash was invented by SanDisk Corporation in 1994.