What does element docking/anchoring mean in QML?

edit

In QML, element docking/anchoring refers to the process of specifying the position and size of an item relative to another item or to the parent item using anchors. Anchoring an item allows it to remain in a fixed position and size relative to its anchor points even when the parent item or viewport changes size. This is useful for creating responsive layouts that adapt to different screen sizes or for positioning overlay items on top of other items. Anchoring can be done using the anchors property of an item and specifying the anchor points such as left, right, top, bottom, center, and vertical/horizontal alignment.