Vacuum sealer has "sous vide" setting; not sure why

I bought a replacement vacuum sealer recently; you can choose from the usual pulse, dry, and moist settings, and this one adds a sous vide setting, and I’m not sure why. The sous vide setting seems to vacuum as well as the dry setting, although it makes a deeper or guttural noise when sucking. User’s manual doesn’t say why there’s the difference nor does the manufacturer support site respond to my emailed queries. Any ideas?

What brand and model, please?

FoodSaver VS3180. And I realize this is a “first world” problem. Eh, it’s not really a problem, it’s curiosity and why someone would go to the effort to include an unnecessary feature. As to this sealer, there’s a bit more learning curve to use this model, plus the hand-held sealer attachment isn’t backwards compatible to their older style containers.