S9: mountain mode vs. basic, customization

I use S9 with SA, not Movescount.
I friend of mine uses Movescount and if he customizes a sport mode, he can select mountain mode. What is this or what is the influence?

Additionally in SA and on watch I recognized that under the sportmodes stands for example basic or mountain mode. Does the watch work there in a different way? For example trailrunning / hiking: basic or Skitouring: mountain mode. What is mountain mode? What does it? Or just wording?

If I do a customized mode, is there a difference if I build it in SA from trailrunning or mountaineering? Mountaineering with „mountain mode“?

THANKS!

@mountainChris No difference, just a different set of fields. Actually, if you build from Mountaineering, I think, FusedSpeed and FusedTrack technologies would be disabled - those are available only for some predominantly running sport modes.

thanks! So there is also really no difference (except Fused Things), if I customize Trailrunning in compare to Running, mountaineering? Is running with Baro or only Trailrunning? Is Trailrunning with baro, because there is standing "basi"2 and not “mountain mode”. Is Trailrunning for mountains? Why does there not stand “mountain mode” under Trailrunning? Just to understand…

sartoric

If I remember well, all the sport modes related to mountain (not only “mountain mode”) should have the barometer automatically set to “altimeter” and FusedAlti ready to kick in, to give priority to altitude changes measurement