These switches momentarily energize magnets in a magnetically held solenoid switch. The solenoid switches are located in your Battery Control Center (BCC). One position connects the battery to the circuit, the other position disconnects the battery from the circuit.
The AUX is the coach battery. It completely removes the battery from the circuits, same thing as if you physically removed the cable from the battery.
The Main is technically a little different, It doesn't completely remove the battery, i.e. starter, hydraulic pump, etc, are still connected, HOWEVER, items that control these are removed, so effectively, its like removing the battery cable. There should be no current flowing through the battery..
Time to use (disconnect).
Long term storage. Make sure the batteries are charged before long term storage.
Shore power - You can also use during long term shore power. Note that this will prevent the batterie(s) from being charged by your coaches 12 volt converter.
Your BCC is probably identical to mine. Here's a manual with diagrams:
Last year when I was evaluating my 12 volt system for boondocking, I traced things out and made a simplified diagram. That diagram is on my web site. Scroll down to "FACTORY WIRING"