It is a great system - off site encrypted backup for all files on your PC. You can set it up to copy what you want and if you have to erase your hard drive and start over because of a crash - Carbonite puts everything back as it was.
I have had to do it twice now and NOTHING was lost either time. Far better than using discs or flash drives like I did before.
Runs about $60-70 per year as I recall. I have been on it 4 or 5 years now.
You can find it by going to carbonite.com.