I believe that the registrar of a domain, in your case example.org must own the authorative name servers for the domain. This means that 1) you can register the domain with whoever you wish - they are the registrar 2) you can create DNS records anywhere on the internet with any name server......BUT they aint gonna mean jack to no-one, the only ones that matter are the onese held by the authorative name server, they are the ones propogated across the net during zone transfers. regarding the third level; if you type in http://example.org you will be taken via an A record to example.org for example: example.org - A - 80.22.243.31 similarly if you then type in FTP://example.org you will visit the same place, but on a different port. and assuming it is configured, you will be prompted for credentials etc. both of these require as explained a single A record to have been created on the authorative nameserver. Lastly, for anything to actually be at example.org, whether its http or ftp you must have a host. this host can be anywhere on the planet, it could be in your house, as long as you have an A record created on the authorative nameserver telling every other DNS server that example.org is at your IP address (also assuming you have the ports forwarded at home lol) I hope this helps, if you have any questions please ask