Does Back up duplicate files during backup?

I haven’t had my SmartWare plugged in for several months and am wanting to run a current backup, however as so much space is being used, I’m curious to know if this back up will duplicate files already on “my passport”.?

 I have photo files on computer that were once backed up already onto SmartWare.  By running backup again will I now have two sets of the same files?  

Hello,

WD Smartware will update the files that have been updated since the last backup and will backup any new files. 

There is an option on WD Smartware “Settings” tab that will make the Smartware save more than 1 copy of each file. You can change that setting at any time.