I apologise in advance for this novice question, but I have searched in vain for a clear and concise description of precisely what the two (S1 and S2) switches do in their respective positions. I understand that at my stage of experience, it is best to leave them both up. I also understand that the right switch, when facing upwards, keeps the Vision in GPS mode. But that's where it all gets a bit fuzzy. I believe one can change the flight mode from within the Flight Assistant software on my PC when the Vision is connected. But what exactly does this do? Please could someone take the time to clearly lay out firstly what these switches do in their various positions "out the box", and then describe how to reprogram the Vision into the more advanced state...and what exactly these switches do once that is complete? You would be doing all us nontechnical types a HUGE favour. And many thanks to all on this forum for sharing their invaluable experience and knowledge.