has terrible flashbacks of jOptionPane
I don't really know. This is a can of worms.
There's some subtleties to it, but people seem to generally have no idea what to call them collectively.
"Pane" seems to refer to window panes, which are the resulting areas when a window is split by dividers. (eg, left pane, right pane)
Panes contain panels. But this seems to be mostly a Microsoft metaphor/term that few others adopted.
Little modular UI things group functions that you can hide, show, dock, resize.
Adobe: Panels
Painter: Panels
Clip Studio Paint: Palettes
Blender: Editors ("Panels" seem to mean collapsible subgroups of textboxes and buttons.)
Maya: Panels
3DS Max: ???
SoftImage: Shelves/Panels? Views refer to different ways of looking at a scene. (a 3D viewport or a schematic view).
Unity: ??? Views refer to the Scene View and Game View. They seem to be refer to the two ways you can view/look at the game world in 3D. Network View is also a thing.
UDK: Docs use the term "panel" once.
But whenever they have tabs, they themselves seem to be subsumed by the word "tab".
At this point, whatever, right?
This is probably not important. Forget I mentioned it. XD