CompactFlash (CF) is a mass storage device format that uses flash memory technology. Produced by Sandisk in 1994, it is commonly used in digital cameras.
Advantages of Compact Flash:
CF cards are considered more rugged and durable and are capable of withstanding more physical damage in comparison to other, flimsier designs. Recently a CompactFlash card was found to be still working after spending two years inside a camera that was submerged in shallow water.
CF cards are available at higher storage capacities than some smaller flash memory cards.
In the case of improper insertion, a card can potentially cause damage to the device receiving the card. However, this rarely happens as slots are usually designed to prevent this from happening.