Secure Digital (SD) cards are physically identical to MMC cards but technically different. The SD card can store and protect copyrighted data, the MMC

Secure Digital (SD) cards are physically identical to MMC cards but technically different. The SD card can store and protect copyrighted data, the MMC card cannot. Some devices can use these two cards interchangeably. Some will recognize only SD cards. These cards are about the same size as SmartMedia cards, but they are thicker.