The first order of business to install rsync on the your Linux box. Drop by the official rsync Web site at http://www.samba.org/rsync/ and get yourself the latest stable release of the software (this tutorial uses rsync 2.5.5).
Once you've downloaded the source code archive to your Linux box (mine is named "olympus"), log in as "root"
[me@olympus] $ su -
and extract the source to a temporary directory.
[root@olympus] $ cd /tmp
[root@olympus] $ tar -xzvf /home/me/rsync-2.5.5.tar-gz
Next, configure the package using the provided "configure" script,
[root@olympus] $ cd /tmp/rsync-2.5.5
[root@olympus] $ ./configure
and compile and install it.
[root@olympus] $ make
[root@olympus] $ make install
Unless you specified a different path to the "configure" script, rsync will have been installed to the directory "/usr/local/bin".
rsync can be used to compare files on the same physical machine, or between two different hosts on your network. If you're planning to sync files between two hosts, you should make sure that rsync is installed on both hosts - simply follow the process above to install the program on each host.
Once you've got rsync installed, the next step is to take it for a test drive.