What is the difference between DVD+R or DVD-R disk

DVD+R allow a single disc be burnt more than one time, adding more files each time.

On the other hand, a single DVD-R disc can be burnt one time only. However, it has much high compatibility, and can be read by most home theatre DVD players.

Therefore, simply speaking, if you are burning computer data, use DVD+R disc; if you are burning movies to be played in a home theatre DVD player, use DVD-R disc.