After you have created a unique Domain Name you have to obtain a
unique IP address. The IP address is assigned by the applicable
Domain Name Registrar, or maybe the web site hosting service.
Generic Top Level Domains (gTLD) are .com, .net, .org, .mil, .gov, .edu
and .int. Special requirements exist for the use of .mil, .gov, .edu
and .int.
Country Code Top Level Domains (ccTLD) are assigned by applicable
authorities for each ccTLD.
A little known fact: The Tonga (.to) authority allows you to
register a domain name for 100 years.