The MMC card or MultiMediaCard was introduced in 1997 by SanDisk Corporation and Siemens AG. At that point the MMC card was the smallest memory card, about the size of a postage stamp, in the market based on flash memory technology. The MMC card is very similar to the Secure Digital Memory Card, actually the SD Memory Card is based on the MMC card. They have almost the same form factor the only differences are that the SD Memory Cards are slightly thicker and they have a write protection switch.
Since the MMC card had slow transfer speed, 2.5 MB/sec, in comparison to other memory cards, mostly compared to SD Memory Card, a new high performance version of the MMC card was introduced in 2005 by the name MMCplus. The MMCplus has today the highest, up to 52 MB/sec, theoretical data transfer speed in the whole memory card industry.
