The simple explanation:
Some systems run better with Vulkan drivers. Some you won't notice any difference. And its quite rare for a system to run worse with them.

This hinges on you actually having vulkan drivers installed of course. Not sure why the option is popping up if you don't, that's just odd.

For my system it only improves the odds of the game crashing. Never crashes if I don't use it.

vulcan works for me better than the the latter.

It may or may not improve your performance depending on your specs, only way to know is to test it. It actually caused lots of graphical glitches on my old system with a 2070.

Do you need to DL this driver from somewhere? Program does nothing/renders nothing when launched with this option...?? Or is this a Windows 10 'only' driver? Win 7 here.

What changes is your frame rate goes up

Originally posted by Drinkcup:

What changes is your frame rate goes up

For some systems, it makes 0 difference with my system.

It's a different graphics rendering system:
https://en.wikipedia.org/wiki/Vulkan_(API)