USING THE FINDER (OS X Leopard)
Note: The Finder is the most important program on the Mac. It is essentially everything you see on the screen when you first turn on the computer, i.e., all the Desktop icons, the Dock at the bottom of the screen where you can click on icons to open programs like Mail and Safari, the Menu Bar at the top of the screen, the Macintosh HD icon, and so on. The reason why it is called the Finder is because it allows you to find things on the Desktop, on the internal hard drive (Macintosh HD), or on a CD or DVD disk that you put in the CD/DVD Drive (the SuperDrive).
TO SEE WHICH PROGRAMS YOU HAVE OPEN:
1) You should see a tiny translucent blue ball under the program button on the Dock for every program you have open.
SWITCHING BACK AND FORTH BETWEEN THE PROGRAMS THAT YOU HAVE OPENED:
1) To switch back and forth between programs, such as between the Mail program and the Safari web browser, click on the corresponding buttons on the Dock.
TO QUICKLY RETURN TO THE DESKTOP:
1) When the Mail program window, for example, is obstructing your view of the Desktop, click on the word Mail at the far upper left-hand corner of the screen, then click on Hide Mail.
2) Note how the word Mail at the upper left-hand corner of the screen is now replaced with the word Finder. This indicates that you are now back on the Desktop and using the Finder program.
3) The confusion starts when you close the Mail window by clicking on the red Close button in the upper left-hand corner of the Mail window, but the word Mail still appears in the upper left-hand corner of the screen. This means that you still have the Mail program open (it is still front and center), but its main window has been closed, and you now have an unobstructed view of the Desktop. To bring back the main Mail window, click on Window, then on Message Viewer.
4) To completely close the Mail program, click on Mail, then on Quit Mail.