It really is not hard to duplicate dvds but if you're a professional you might need these several tips. The concept of DVD duplication is to take the information, music or audio from a DVD and to use dvd cd rw burner to burn all of the files and data from the original, or mastered DVD, and into a new DVD.  When one does this for a couple of disks, it creates not only the burning of a DVD, but also duplication that uses links to towers and which allows for several DVD to be burned at one time. I usually use and try to duplicate audio cassette to dvd but at times it is really difficult. I have yet to find that super software that makes it easy on my MAC.