SYNC usually means that any change on either side will propagate to the other side, a bi-directional sync if you may. Bvckup2 is a unidirectional sync... basically a file replicator.
Here is a little open source mirror and/or multi dir sync program...Freeware by 'Alternate Tools' called 'Alternate File Move' (Alternate File Move 1.880) (FileMove.exe) Not fancy but I found it functional. If you choose to try it please read all the help file and contents, and see how to enable logs etc. File Move seems safer, than some, in respect of it will show you an 'analyze', 'check again' and report, before finally committing files and/or folders, to move to the destination. The GUI info is a lot clearer and (in my opinion) simpler than most paid programs. Versionnumber: 1.880 Filesize: 1099.06 Date: 30.08.2017 MD5 value: 888536e1d69275eaf8895293ca95152a Supported operating systems: Windows NT 4, 95, 98, Me, 2000, XP, Server 2003, Vista, Server 2008, 7, 8, 8.1, 10 Languages included: English, German, Spanish, French, Chinese, Swedish, Arabic, Italian, Greek, Russian, Japanese, Hungarian To try it I just made a couple of folders named A1 and A2 under C:\ There is a 'show report when done' in 'options' and filled A1 with copies of files that aren't significant but were fairly large to test and mess about with without threatening my real or important files. I haven't tested it extensively so I am not recommending that people do anything but it's just to bring it to your attention if you are not already aware of it. Virus Checked clean with Avast Pro. Running on 32 bit Xp sp3 system