If either the new width or height is different from its old value, XtConfigureWidget calls the widget's resize procedure to notify it of the size change; otherwise, it simply returns.
The XtMoveWidget function returns immediately if the specified geometry fields are the same as the old values. Otherwise, XtMoveWidget writes the new x and y values into the widget and, if the widget is realized, issues an Xlib XMoveWindow call on the widget's window.
The XtResizeWidget function returns immediately if the specified geometry fields are the same as the old values. Otherwise, XtResizeWidget writes the new width, height, and border_width values into the widget and, if the widget is realized, issues an XConfigureWindow call on the widget's window.
If the new width or height are different from the old values, XtResizeWidget calls the widget's resize procedure to notify it of the size change.
The XtResizeWindow function calls the XConfigureWindow Xlib function to make the window of the specified widget match its width, height, and border width. This request is done unconditionally because there is no way to tell if these values match the current values. Note that the widget's resize procedure is not called.
There are very few times to use XtResizeWindow; instead, you should use XtResizeWidget.