How do MultiMediaCards differ from SD cards and other memory cards?
A: MultiMediaCards and SD cards are based on separate but related industry standards. They are similar in size and appearance except that MultiMediaCards are thinner and have fewer contact pins. Similarities in the standards allow MultiMediaCards to be used in electronic devices with expansion slots that are made for SD cards. However, SD cards cannot be used on devices with slots made specifically for MultiMediaCards. Low-cost read-only memory (ROM) is available as MultiMediaCards but not SD cards. MultiMediaCards are not compatible with other memory cards such as Memory Stick and CompactFlash, since they are based on unrelated standards.