Note however that the Mac OS X Menu Bar will show only one application in the Menu Bar at any particular point in time despite numerous applications running simultaneously.  Please read the following guide - What is the Menu Bar? for an explanation.

When you switch between applications, the Menu Bar changes accordingly.  Note that if you were running the Safari web browser and iPhoto and switched from Safari to iPhoto,  the Menu Bar would show iPhoto while Safari continues to run in the background.  Safari won't pause or become idle.  This in part is due to Mac OS X's multitasking capabilities.  Multitasking as the name implies, allows you to do multiple tasks at the same.  For an operating systeme, this means you can run multiple applications at the same time.

For example, you can download files from the Internet with Safari as you view photos in iPhoto and listen to music in iTunes.  All will be active applications but the Menu Bar will only show iPhoto as you use iPhoto.

One way to see all application windows would be to invoke Exposé or Activity Monitor.  You can also switch to another application by pressing Command and tab simultaneously.

Updates

• May 1, 2009 - content revision