Go to the Apple menu up
at the top left of your screen and click on About This Mac. A small window
appears that tells you some basic information about your computer. The
bold text saying Mac OS X, refers to the operation system of the computer.
If you click on the words Versions 10.5.6, the text will change and display
the build of your computer, click again
and it will display the serial number. Below that is a Software Update
button. Click on it to have the computer check for new updates. About
this Mac also tells you the processor, memory and starup disk of your
computer. This information is really helpful if you are on the phone
with Applecare or if you are looking to upgrade your system. Clicking
Info will take you to the System profiler, which covers more specific
technical information about your computer. For more information please
watch the System Profiler video.