DVD - R + or-

Different recording formats.

Interesting question, my answer is different recording methods rather than formats, as both are found to be completely compatible by any DVD player, both being labelled I believe "VIDEO_DVD".

Both are readable in ANY DVD burner or ROM at this point, in fact I believe that once burnt, there is no more differences to find!!

Its only when burning a DVD that you need to have a compatible disk in some single mode type burners.....other Burners will burn all formats, including RAM.

DVD+R have/produce significantly less errors that DVD-R formats, that has been shown several times in completely separate testing both by the C'T Magazine and the ComputerBild here in Germany. It is nothing to do with the manufacturer per Se either.......which I why I always buy + versions, but my burners can handle all types.....

Oh not true. I admit I purchased low end software but it said in the instructions, on the box and in the program itself that -R or +R would both work. But Noooo, after much trial and error, mostly error, only the +R worked with this program/Burner.

Both have the same function,but have different structures.

The problem was 99.9% your Burner hardware, it was only licensed to burn +R & +RW disk. Benq do this and some other companies as the License fees for - Formats was so high....

Read the hardware manual for your burner.

Another possible reason is down level firmware in the burner......do an update asap.

The difference goes deep: to start from the design idea: DVD +R/+RW is designed so that a normal DVD-player would not see the difference, except for a minor detail: reflection level. (later more)

This is done as the DVD standard was set and many DVD players were already leaving the shops. Then the DVD+RW consortium was formed and they started to outline the specifications.

This consortium had nothing to do with DVD so after a few discussions the DVD was thrown out of the name. From now on it was +RW. the same group came later with the +R disks based on the same basic technology as used in +RW.

In the meanwhile the DVD design group started to work on DVD-RW (and DVD-R), they drafted a complete new DVD standard with the idea that a recordable disk would only be played in a recorder, a simple player would not accept them. This to avoid massive illegal copies. As the mayor film distributors were part of the group this was quite normal, many of them lost quite some money on CD-R.

As the groups were somehow a bit mixed they knew each other techniques and some die hard DVD-R fans started to build in a way to recognize the +RW disks. This could be done on reflection level as the disk reflects at the same level as a double layer DVD and no double layer could be found.

The big differences are the way a sector is addressed: Frequency or Phase modulation in the groove wobble, this is requesting special decoders and servo circuits who can work with the specific encoding.

Secondly +RW/+R does not have a block separation zone, they need to be written all exactly after each other (playability), DVD-RW/-R has an allowance zone, reducing the amount of info to be written on the disk and invoking the old players to refuse the disk.

We are now 5-6 years further and the playability is equal for all types, all recorders accept the different disks.

Oh yes: DVD is read & written in a constant linear velocity, DVD-RAM in a constant angular velocity.

http://en.wikipedia.org/wiki/Dvd-r