These two menu items are fairly self-explanatory. Close closes the frontmost window and Quit quits the Sloop Rudder application.
If you have changed preferences but not saved them yet, and you choose Close or Quit, the Sloop Rudder will ask you if you want to save them before closing / quitting.
Please note that the main preferences dialog box is always open while the Sloop Rudder is running. Closing this box is equivalent to quitting the Sloop Rudder.
If you are using the Sloop Rudder when the Sloop Sail is not installed, the help facility is always open. Closing the help window in this case is also equivalent to quitting the Sloop Rudder.
