It won't take long to realize that Mac OS X has only one Menu Bar and that it is always positioned at the top of the screen.  This is in stark contrast to Windows environments where each application window has its own dedicated menu bar.

Menulets are of small icons located at the upper right corner of the Menu Bar.  Many Windows users are accustomed to the Windows taskbar that is located on the lower right corner of a Windows screen.  Menulets are similar to the taskbar icons in Windows.

The most important Menu Bar in Mac OS X is the Apple Menu, it's located on the far left and can be easily identified by a Blue Apple icon.