rsync can do many more things that are beyond the scope of this book. One of its most significant abilities is acting as a network server. Such a server offers several modules that you can call by symbolic names instead of pathnames. You can also offer public read-only access to the modules; this is a nice alternative to anonymous FTP.
Another important feature is rsync batch mode operation. Although it is fairly easy to write scripts containing rsync commands to do network file distribution, rsync can also employ a number of auxiliary files related to command options, logging, and transfer state. In particular, the state files make long transfers faster, and easier to resume when interrupted.
There are also many more command-line options than those described in this chapter. To get a rough overview, run rsync --help. There is more detailed information in the rsync(1) manual page as well as at the rsync home page: http://samba.anu.edu.au/rsync/.