tried to activate- invalid license

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

I recorded a video on my phone that's turned sideways when played. How do I rotate it to play on my computer?

How to download youtube videos onto my mac easily, and for free?

osx will be up dated in a week..will this app still work or are you going to do an update soon?

I check Audio in Settings but no audio downloads from youTube.  I have tried different codecs, but its always the same.

Can I download and burn music from ituns on to a CDR?

How much video can a 30gb ipod video hold? What's the minimum and maximum?

Movies and the roles/actors (actress)

I would like to attached videos to my email but the videos are unable to be downloaded completely.