Macros
Macros are the modules that you design yourself, or that are designed by someone else. At any rate they have their internal structure which is available for viewing and editing. Macros are stored in files with .smm extension. E.g. MoogFilter.smm.
A macro module has a number of inputs and outputs (zero or more). E.g. the MoogFilter macro could have the Cut input for the cutoff, Res input for the resonance, In input for the input signal and Out input for the output signal.
The macro's internal structure modules receive the signals from the macro's inputs and send the signals to the macro's outputs.
A macro module can have no panel, have its own panel, or have its own panel as a parent's panel subpanel (appearing in a frame).