"MMC memory" stands for MultiMediaCard, a type of portable computer data storage that came around in 1997 but has been concealed by Secure Digital (SD). It comes in a wide range of sizes and specific uses.

• Open Standards
MMC is an "open" standard, which means that an MMC manufacturer doesn't have to pay royalties to a patent holder. Though, a manufacturer should pay an annual membership fee to the MultiMediaCard Association (MMCA).

• Voltages
MMC also be at variance from SD by offering a 1.8-volt version, in place of just a 3.3-volt version. This means longer battery life for the device using an MMC card.

• MMCplus
An MMCplus card can transfer data at up to 416 MB per second (Mbps), while a regular MMC card tops out at 20 Mbps. Software linked to slots designed for earlier MMC cards requirements to be updated to take benefit of MMCplus speeds.

MMCmicro
• For very tight spaces, there is the MMC micro card, which is about the size of a postage stamp. However, it is not suitable with microSD card slots.