The right part is made up of buttons including :

Categories
opens a window which lists all the defined categories and rules.

Files
opens a window which lists all the system files on the selected volume.

Preferences
displays the preferences dialog.

Help
you're reading it !

Tidy It Up !
launches the tidying up process.


A double-click on a volume's icon is a short cut to quickly open the category window and the files window.