Zorro 1.60 has these two options for Oanda broker.
How exactly are these two different?

Sorry if it is a dumb question! I was not able to find anything about this in the manual and on this forum.

V1 is old and V20 is the newer API.

Thanks for the reply!
But why keep an old version? What purpose does it serve?

The same reason why Microsoft still supports Windows 8 when it is trying to sell Windows 10.

If Oanda shuts down their V1 API and launches their V20 API all at once, everyone gets angry. There must be a transition phase. Programmers need to write new code before they can jump ship - and all the while still using the old interface.

I see, that makes sense, thanks!
In short, there is no difference for the end consumer, only for the Zorro devs. Good to know.

Hi Hredot. Actually, there is a difference: Many end users prefer to continue running the old, presumably more stable version for a time while those who need the new features or just prefer to be on the bleeding edge accept whatever extra risk there may be in working the bugs out of the new version...