Differences between DVD +R and -R

What is the difference between DVD+R and DVD-R?

I notice that many people keep asking this question on yahoo answers when they are using DVD recorder and DVD burner, and these two recorder format are really very similar and could be confusing. So if you are still unclear about the difference, just read on for details.

As of June 2006, there is no physical difference between a DVD-R/-RW disc and a DVD+R/+RW disc. There is, however, a series of technical differences between DVD-R/-RW DVD+R/+RW recorder format. The DVD+R/+RW format offers subtle extra functionality for people who record their own movies and data.
The Standards Differences
Both formats can be written once, and the truth is that the two competing technologies use different formats. No single company "owns" DVD and both technologies have their "champions".

DVD-R (pronounced "DVD dash R") and DVD-RW are officially approved by the standards group DVD Forum which was founded by Mitsubishi, Sony, Hitachi, and Time Warner, so it has tremendous industry support for its technical standards. DVD-R is supposed to be slightly better for videos and movies as widely accepted by home DVD players

DVD+R ("DVD plus” R) and DVD+RW formats are not approved by the DVD Forum standards group, but are instead supported by the DVD+RW Alliance. The DVD+RW Alliance are supported by Sony, Yamaha, Philips, Dell, and JP, so it also has tremendous industry support for its technical standards. Note that Sony supports both organizations. And DVD+R is supposed to be slightly better for data, because the data can be added later (not rewrite, but still accessible) if the disk has enough room.

The Main Functional Differences
1) the DVD recorder's built-in defects management
2) the way the recorders format and rewrite DVDs
3) the price.
According to the claims of the DVD Alliance, DVD+R recorder will let you:
1. Instantly eject without having to wait for finalized formatting.
2. Ability to record one DVD disc partially on PC and partially on television.
3. Background formatting: while the disc is being formatted, you can simultaneously record on already-formatted portions of the same disc.
4. Enhanced ability to edit filenames, movie and song titles, and playlists.
5. 100% compatibility with all other DVD players, while still enjoying these extra recording features.