Three finger swipe to switch between open applications

[ShalokShalom]

My girlfriend loves the gestures to swap between applications with three fingers, and that`s why I like to install Touchegg.

Now I read that the default setting for this gesture is to swap between virtual desktops, and I ask myself why. Is it, that macOS actually uses virtual desktops, and that applications open by default on their own virtual desktop?

Or is it that Touchegg can not swap between applications?
Is it possible to switch between apps like I do with Alt + Tab?