1. Open Disk Utility (Applications > Utilities > Disk Utility)
2. Select the Disk Drive or the DVD from the volume list on the left.
3. Create an image of the CD or DVD by clicking on the “New Image” button
4. Name your disk image (or leave the default), select “DVD/CD Master” from the Image Format menu, and click Save.
You’ll get a dialog box showing the progress of the disk image creation.
When it’s complete, you’ll see the new disk image in the list of volumes in the left pane.
5. Eject the disk, insert a blank disk.
6. Select the new disk image in the volumes pane.
7. Click “Burn”
You will then get a Burn dialog box. When it’s done, you can keep copying disks, or trash the disk image you created.
You’re probably asking, “Why didn’t they just give me a ‘Copy Disk’ button?” Think about it. This way is more powerful. You get to dictate how to create the disk image, where it is stored, etc. When you’re done, you can burn as many disks you need without having the original. Sure it takes more steps. But, it opens up many possibilities.