Is there a difference between burning video and data DVDs? I know you need to pick the right type in Nero, but what's the difference between the 2 types, and is there really a difference?

I recently burned a DVD using Roxio by just copying the VIDEO_TS directory to it, it plays fine in a DVD player and is recognized properly as "DVD video". Is this the right way to copy a DVD (we are talking home-made videos, so there's no encryption issues), or am I just lucky that it's working?

Thanks,
GK