An electronic flash memory storage disk commonly used in consumer electronic devices such as digital cameras, MP3 players, mobile phones, and other small portable devices. Types of memory cards include PCMCIA, CompactFlash, SD Card, MiniSD, xD-Picture Card and others. Memory cards are usually read by connecting the device containing the card to your computer, or by using a USB card reader.
See also “Different Types of Memory Cards” in the “Did You Know…?” section of Webopedia.