This line resolves the hostname for the server. This file forms the heart of Apache server. Though there are comments included in the file itself, don't make any changes unless you are sure what you are up to. Listed below are some changes that are necessary to get the server working. The first 50 odd lines shall have a list of the various modules.
Modules are small programs that help to build up a fully functional server.
Ranging from Custom 404 Error Messages to SSI directives, one can configure them as per requirement and even add their own modules if desired. Keep the above settings as they are. If anything goes wrong then an email is sent to the address specified above. Though it can be set to a particular domain name or IP, giving it a wild card just eases the task if you plan to setup multiple hosts. The remaining things are self-explanatory and should not be changed.