Clone mode will create a bit for bit bkup as calcu007 said (minus the copy protection of course).
It will preserve the layer break…regardless of whether or not [B]Remove layer break [/B] (Common Settings) is ticked or unticked.
It also has the option of copying DVD video data only…or not, depending upon your selection and specific needs.
Full Disc will copy all movie, menu and trailer content either to a dvd5 or dvd9, ie., compressed or non-compressed, again depending upon your selection.
All this information has been discussed many times and is available in the tutorial or by using the search function.
Please use these tools.