What is MMI?

MMI can refer to multiple technologies depending on the context. It is most commonly used to refer to Man-Machine Interface (now often called Human-Machine Interface or HMI), which is the means by which humans interact with a machine, device, computer program or system. It encompasses both hardware and software components that allow user input to be interpreted by the system and system output to be presented to the user. Examples include graphical user interfaces (GUIs), touchscreens, voice control systems, and even simple switches and displays. Another possible meaning for MMI is Multi-Mode Interference, a phenomenon used in integrated optics for creating compact optical devices such as splitters and combiners. Without more context, it's difficult to be more specific.