Curious question: resolution independence

[Jud Craft]

The development list is probably not the place for simple queries, but
I haven't found it anywhere else and not sure where to look.  Since
plasma is the default KDE environment after all...

Is the KDE desktop resolution independent?  I know that Plasma uses a
ton of scalable graphics (from general info), but I haven't heard
anything about actually using that scalability besides when resizing
the panel.  In addition, that doesn't mention whether the Oxygen
graphics (or even Qt widgets, I suppose) have such a feature.

As an aside:  in reference for such things, will there be certain,
specified size-steps defined for the panel, as opposed to free-form
stretching (which does cause some elements to occasionally look
distorted or out of place)?  I'd imagine it would require a reference
size (some sort of middle-resolution, 96 DPI desktop for example --
where standard sizes (16x16, 24x24, and 32x32 icons) are readily
visible.