rsync is a utility for fast incremental file transfers. If you want to install it, the instructions can be found in Chapter 22 - rsync-2.6.2. Note that if you only want to use the client, you do not need to run the server and so do not need the startup script and links. In accordance with good practice, only run the server if you actually need it (and if you don't know whether you need it or not, it's likely that you don't!).