A list of the all the help topics available to you arranged like the table of contents in a book. The topics are contained in books which open-up into a hierarchy reflecting the structure of the On-line manual.
Use the left button of your mouse to click the Book icon in order to open (or close) its list of topics
Use the left button of your mouse to click the Page icon in order to display the topic in the right frame
Use the right button of your mouse to right-click the icon in order to display a popup menu allowing you to:
Print the page or save to a file