Mechanics Q: How does Horitzontal scroll work?

Trying to better my understanding for future design of how horizontal scroll works.

In repeating groups, I seem to be able to get everything to stay on one line and result in horizontal scroll when there is more data than can fit on the page, but with normal groups they wrap.

What is the fundamental difference that makes these two, seemingly quite similar, elements behave so differently?

And is there a way to stop normal groups wrapping, and instead result in a horizontal scroll?

I may be missing out but I haven’t seen a group that would result in a horizontal scroll. Only repeating groups.