is a flexible program for efficiently copying files or
has many options to select which files will be copied
and how they are to be transferred. It may be used as an
ftp, http, scp
The rsync remote-update protocol allows rsync to transfer just
the differences between two sets of files across the network link,
using an efficient checksum-search algorithm described in the
technical report that accompanies the rsync package.
Some of the additional features of rsync are:
Support for copying links, devices, owners, groups, and permissions.
Exclude and exclude-from options are similar to GNU tar.
A CVS exclude mode for ignoring the same files that CVS would ignore.
Can use any transparent remote shell, including rsh or ssh.
Does not require root privileges.
Pipelining of file transfers to minimize latency costs.
Support for anonymous or authenticated rsync servers (ideal for