Timeshift for Linux is an application that provides functionality
similar to the System Restore feature in Windows and the Time Machine
tool in Mac OS. Timeshift protects your system by taking incremental
snapshots of the file system at regular intervals. These snapshots
can be restored at a later date to undo all changes to the system.

In RSYNC mode, snapshots are taken using rsync and hard-links.
Common files are shared between snapshots which saves disk space.
Each snapshot is a full system backup that can be browsed with a
file manager.

In BTRFS mode, snapshots are taken using the in-built features
of the BTRFS filesystem. BTRFS snapshots are supported only on
BTRFS systems having an Ubuntu-type subvolume layout
(with @ and @home subvolumes).