Rsync
On this page 1 section
Rsync can be use to syncronise files and directories with each other on the same machine or on multiple different machines inteligently.
Here are my commands for moving files across to my NAS from the SeedBox.
rsync -cavh -P --remove-source-files /home/ed/storage/movies/* [email protected]:/mnt/Neo/Movies/ToSort/ > /home/ed/movies-rsync.log 2>&1 && find /home/ed/storage/movies/* -depth -type d -empty -delete