Movies and the roles/actors (actress)

What's the differences of the following:
DVD-R, DVD+R, DVD-RW, DVD+RW and DVD-ROM?

I DOWNLOADED itunes but when i go on itunes.com, how can i get to my account, and my files, library?!??!

All the video players on my computer suddenly couldn't open any avi video files. I don't know when does it happens. I've tried Windows Media Player, Quick Time, VLC Media Player and DivX. I installed K-Lite_Codec_Pack_660_Full instead of teh ffdshow. But these didn't change anything. I also tried the Shark007 5.8.6 codec pack but it still didn't work. My computer runs Windows XP Pros 2002 SP3. Please help me, thank you!

I recently bought some music on my I phone. Now I have a new computer. Who can tell me how to sync the music library on both my computer and my phone without deleting all of the newly bought music. I tunes tutorials are useless to me... don't know what to do :(

to register the program and to start the converter you have to input the license email? the license email is a normal email and if I copy this email, the programm answers "wrong format". What should I do?

I've created my own movie recently, and I wonder how to turn it from 2D to 3D? I only shot the video with one camera, so I cannot re-shot the whole video again.

How shall I choose between Samsung Galaxy S4 and iPhone 5S?