Just hold your mouse over each button for a brief explaination of each function in a "tooltip." One thing to note is that the undo/redo buttons tell you in the tooltip what function is available for undo/redo.
To the far right of the shortcuts bar are two large buttons for switching from the photo browser to the date view of Organizer. We'll look at date view closer in another lesson, but feel free to explore it on your own any time.
