Various information is displayed depending on which options are selected.
If no options are chosen, -stats is assumed. There is also a special -root option to quickly obtain information on the screen's root window. This is very useful in debugging X applications where the target window is not mapped to the screen or where the use of the mouse might be impossible or interfere with the application. This option allows the user to specify that the window named name is the target window on the command line rather than using the mouse to select the target window. This option specifies that X's root window is the target window.