[REBOL] System object?

[max82]

Hi,
another newbie question:
how do I use the system object? Could somebody please explain to me how the
reboldoc script works? I previously assumed that it did a "help" for each
function, but there isn't a help command anywhere, so what does "help"
_really_ do? Also, is there a way to make or get a complete map of the
entire system object?