Synchronize Files With Unison On Ubuntu / Debian

Unison is a free, cross platform file synchronization tool that enables us to keep two set of file replicas (instances) on two different systems or on different disks of the same system. Unlike simple mirroring or backup utilities, it updates both replicas of a distributed directory structure. It detects and displays the conflicting updates. Unlike a distributed filesystem, Unison is a user-level program; there is no need to modify the kernel or to have root user privileges on either host