Specifying what happens when you insert a CD or DVD can be useful. The "CDs & DVDs"
preference panel lets you change these functions. The options shown
below those available with a SuperDrive. These options may vary depending
on which type of drive you have in your computer.

With each of the options, you are able to do one of five different things.
"Ask what to do" will have the computer ask you
what to do each time you insert that type of disc. If you check the box "Make
this action the default", you will change the setting for that type of
disc in the "CDs & DVDs"
preferences.

Open Application Name
Opens the specific application. Use this option if every
time you insert this type of media you want the specific application to open.
By default, there are some specific applications already listed for each media
type.
Open Other Application
Will display a list of all of your applications
and let you choose which application to open the media with each time.
This will set it to always open that application
when the media is inserted.
Run Script
Will give you the option to select and open an AppleScript applet
that should open whenever you insert that type of disc.
Ignore
Tells the computer to do nothing when you insert that
type
of disc.