I get sample .iso left picture. It have capacity 6 Gb to burning in DVD. When you have something software burning such as Nero, it will help you to create DVD from media file (.iso).
The first step to burn, average capacity of Dvd have 4 Gb. So you must buy 2 pieces for "total success" burning to DVD. After you see the file that you want to create to DVD, open your Nero StartSmart and choice Copy and Backup. See the Burn Image to Disc like a picture in below.