I've got a drive which I want to back up (I've decided to give LaCie's "Silverkeeper" a go). The original drive is an external 1TB drive which contains just data files (audio, video, text, images etc.). No system files, user area, not bootable etc. The backup drive is an external 2TB drive. So far I've used Silverkeeper to copy the entire contents of the 1TB drive meaning they contain the exact same files/folders. So far so good Since then I've added some new files to the original drive and possibly reorganized a bit as well (moved files/folders around), so I'm wondering what I should do now in order to back up my changes? Should I use "Backup set" or "Synchronize set" for this, and what's the difference between the two, and is there a way to make it back up in a similar way to Time Machine where I can go back say 2 weeks and find a file that I deleted from the original drive say 3 days ago? Is this what the "Copy set to folder" option ("Options" tab in Silverkeeper) does, and the "No. of copies" indicating how many backups back in time I want to keep before the oldest one is overwritten?