Apple, for a very long time, had a little triangular doohickey at the lower right corner of each window, and to resize the window, you grabbed it and drug.

Windows, most of the time and still does, have a thing where you can grab any edge or corner of any window to resize.

Windows, in recent years, sometimes, only on some windows, only in some apps, you see a little copyright violation of Apple's windows in the lower right corner of the window and you can grab and drug that triangly thingy too. In addition to grabbing and drugging the edges.

Questions:
- Little triangle-y druggy grabby handley thingy doohickey in lower right window corner: WHAT IS ITS NAME?
- Can this thingy (whatever its namey shall be) be added by the Windows API to any window? Is it a built in thing in the API in recent years? Like, I dunno, set by a flag in the extended window styles by the SetWindowLong function or some such?

I tried googling for the latter, and was hampered in that process by the former.