Unison is a file-synchronization tool. It allows two replicas
of a collection of files and directories to be stored on different
hosts (or different disks on the same host), modified separately,
and then brought up to date by propagating the changes in each replica
to the other.
Snaps are applications packaged with all their dependencies to run on all popular Linux distributions from a single build. They update automatically and roll back gracefully.
Snaps are discoverable and installable from the Snap Store, an app store with an audience of millions.
Enable snapd
On Debian 9 (Stretch) and newer, snap can be installed directly from the command line: