How do I copy a DVD to another DVD on a MacBook Pro?

Here's how:

1 - insert the DVD in the option drive and launch Disk Utility.

2 - select the DVD disc in DU's side pane and use the File ➙ New Image ➙ Image from "XXXX".

3 - when the disk image is finished Control (right) - click on it and select "Burn to Disc" in the contextual menu. Burn the disk image to disk at the slowest speed available (2x-4x) to assure the best burn quality.  Always use top quality media:  Verbatim, Maxell or Taiyo Yuden DVD-R are the most recommended in these forums.

Is this a video DVD? If so is it a commercial one or one that you created?

What system are you running?

What Model and year is your MBP?

Does it have a built in optical drive?

If not do you have an external optical drive?