MMC (MultiMedia Card) is a compact flash memory card format introduced in the late 1990s as a universal data storage solution for electronic devices. Initially used in digital cameras, early mobile phones, and portable media players, MMCs were also adopted in some embedded systems and industrial devices.
Physically similar to SD cards but thinner and based on a different communication protocol, MMCs support both serial (SPI) and parallel bus modes, making them compatible with certain microcontrollers. Over time, MMC was largely replaced by SD cards, which offer higher capacities, faster transfer rates, and broader compatibility.
