According to the book I read (McLaren, et al, 2000), the InterNIC Web site at
http://www.internic.net is responsible for domain name registrations. The domain names which most of the organizations do choose, contain a form of organization’s name; to make the site’s owner easy to identify from its address. For instance, the government of my city has its domain name of naga.gov, the school I graduated has its domain name of AdNU.edu, and many others. However, some companies register more than one name.
Noticeably the three last letters in each domain name is an abbreviation, which designates the type of organization that owns the site.