Is it possible to start the OS from CD

[jasonlizard]

I guess the answer is 99.999% no but I need to ask. Is there a possibility for a Mac, which has OS X, to be started from a CD(a different Mac OS version) instead of the OS installed on the machine? Thanks in advance.

 

[motulist]

Sure, just put in any model-compatible OSX install disc (cd or dvd) and start the computer up while holding down the letter C on the keyboard.