Originally Posted by crayola

Some thoughts…

Sync
+ Because that way your files are available for immediate access if your primary down fails.
+ To have the same data set on more than one computer.
+ It's possible to make a boot drive.
+ If you backup to a NAS you can access all your computer files from over the Internet.

Backup
+ Compression.
+ Encrypted archives.
+ File history – same file with different snapshot dates.