The rsyncd.conf file controls authentication, access, logging and available modules. A module begins with the name of the module in square brackets and continues until the next module begins. The file contains some global parameters like motd, syslog etc. Others are module related. In the above configuration, a square bracket represents the module for a particular dir, which is generally backed up.
Comments are any user related info.
Also for a server to check whether it is running Rsync server or not. You can put such lines according to your requirement in a file and run through cron. The above configurations have been tested on Red hat Linux 6.2 kernel 2.2.14. The comments are owned by the poster. We aren't responsible for its content.