A toplevel widget or window is similar to a frame except that it is created as a top-level window, i.e. its X parent is the root window of a screen rather than the logical parent from its path name. The primary purpose of a toplevel is to serve as a container for dialog boxes and other collections of widgets. The only features of a toplevel are its background color and an optional 3-D border to make the toplevel appear raised or sunken. See window.