MDesigner: Live mode
From Microduino Wiki
The primary methods of using Microduino modules with mDesigner is with Live and Arduino mode. Each mode as it own pros and cons. Determining the right mode is up to the user per use case.
Live mode is regular Scratch, but with added blocks which are designed to interact with Microduino modules. This means the user has access to the stage and actor blocks. The script is ran in "realtime"
Arduino mode in which the stage and actor are disabled. This mode acts as a "visual" drag and drop coding editor. The script (code) is converted to "Arduino" code and then compile and uploaded to the attached Core module. This means that code can run even when detached from the computer.