A Secure Digital (SD) card is a tiny memory card used to make data storage portable among various devices such as car navigation systems, cellular phones, eBooks, PDAs, smartphones, digital cameras, music players, camcorders and personal computers. An SD card features a high data transfer rate and low battery consumption, both primary considerations for portable devices. It uses flash memory to provide nonvolatile storage, which means that a power source is not required to retain data stored.
