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 specifies that X 's root window is the target window. This is useful in situations where the root window is completely obscured.