I have a Dell Studio 1558 with "roxio burn" whatever that means, I don't know. I want to burn my video on to a DVD but don't know whether to get DVD+R , DVD+RW , DVD+R DL , DVD-R , DVD-RW , or DVD-RAM . What are the "+" and "-" for??!! what is the difference??

I've tried to look it up on the "roxio burn" in my computer, but it doesn't seem to have anything about it just says to put cd in drive. I just want to be able to burn my video on a DVD and be able to watch it on a DVD player, xbox 360 or any computer. Thanks.