I'm on the external hard drive search (which is another thread) and that has led me to a kazillion questions... I'm wondering what the difference is between having two external hard drives - one backing up the 1st hard drive and the internal hard drive (you can do that right?) and a RAID system. Now, a RAID is supposed to be mirror imaging right? Does it mirror image your internal drive as well? Or is it a backup to a backup? Any benefit to going RAID or not?