domain name Looking for a domain name? You'll find it to the right of the @ sign in an email address, or about ten characters into a URL. CNET's domain name is cnet.com. The domain name of daemous@pentagon.io.com is io.com. Domain names are issued by the National Science Foundation (NSF), and they come with different extensions based on whether the domain belongs to a commerical enterprise (.com), an educational establishment (.edu), a government body (.gov), the military (.mil), a network (.net), or a nonprofit organization (.org). Some domains use a geographical notation too (such as the San Francisco, California-based well.sf.ca.us).