I don't know if this is a feature or a bug.
If you drag any folder and drop it between the leftmost icon on the desktop and the edge of the screen, the contents of the folder will appear as a vertical toolbar down the left edge of the screen.
Dragging the toolbar anywhere creates a toolbox full of icons.
To close it, right click on it and select close.
If you drag any folder and drop it between the leftmost icon on the desktop and the edge of the screen, the contents of the folder will appear as a vertical toolbar down the left edge of the screen.
Dragging the toolbar anywhere creates a toolbox full of icons.
To close it, right click on it and select close.