If you don’t have webspace then this section allows you to setup subdomains to redirect to external urls. You can either use standard redirection of masked.
For hosted domains this section will allow you to setup subdomains in your webspace – setting these with the default folders will mean they are setup in their own folders with full cgi-bin and php support. They are useful for sub-sites that require their own php configuration.
Note: If you wish to use WordPress with subdomains then use the WordPress installer which creates the subdomain during the install process.