Compact Flash is a small, removable mass storage device used in portable electronic devices. It's a popular card choice for use with personal digital assistants (PDAs) and digital cameras, but not only that. The card weigh a half ounce (about 15 grams), it have the size of a matchbook or even smaller (the latest models) and it was first introduced in 1994 by SanDisk. The card provide complete PCMCIA-ATA functionality and compatibility. Most Compact Flash devices contain a flash memory in a standardized enclosure, the cards are designed with flash technology - that's a nonvolatile storage solution that does not require a battery to retain data indefinitely.

Compact Flash storage products are solid state, they contain no moving parts and provide much greater protection of the stored data than conventional magnetic disk drives. They are five to ten times more rugged and reliable than disk drives including those found in PC Card Type III products. CompactFlash cards consume only five percent of the power required by small disk drives.

When Compact Flash was first being standardized the hard disk were rarely larger than 4 GB in size, so the ATA standard were considered acceptable. Since then there ore 6 different revisions, every one adding several features that improved the CF. For example, the CF cards manufactured after the original Revision 1.0 specification were available in capacities up to 128 GiB (137 GB). The Compact Flash card specification version 4.1 supports data rates up to 133MB/sec and capacities up to 137GB. Compact Flash revision 5.0 (2010) added some features including 48-bit addressing (supporting 128 Petabyte of storage), larger block transfers of up to 32 Megabytes, quality-of-service and video performance guarantees.CompactFlash Revision 6.0 (November 2010) added UltraDMA Mode 7 (167 Mbyte/s), ATA-8/ACS-2 sanitize command, TRIM and an optional card capability to report the operating temperature range of the card. While this current revision works in [P]ATA mode, future revisions are expected to implement SATA mode.

CompactFlash provides the lowest cost flash storage solution. A wide variety of low cost flash technologies can be used with the built-in controller. These controllers lowers costs further by reducing costs in the host device and allowing defective flash chip cells to be mapped out, thus increasing flash chip yields.

The physical format is now used for a variety of devices, since CompactFlash became the most successful of the early memory card formats, surpassing Miniature Card, SmartMedia, and PC Card Type I in popularity. Proprietary memory card formats for use in professional audio and video, such as P2 and SxS, are physically larger, faster, and costlier.

When compatibility, interoperability, reliability, cost, and performance count CompactFlash cards are the ATA-compatible solution that delivers.