History of domain names: Once upon a time, there was no Internet. But even when it came into being, it wasn’t in a completely finished form. Read along to find out how the domains changed over time.

Creating Order

One of the early steps in the design of the Internet was to create the designations that would hierarchically organize the domains. This has been a growing, changing organization, but the current understanding of the Internet Assigned Numbers Authority (IANA) is that there are three types of top-level domains (TLDs)—the highest level of division on the Internet which are always the final element in a domain name, whether it stands alone, is part of an e-mail, or forms the end of a URL. They are:

• country code top-level domains (cTLDs), two-letter domain names that are for countries or dependent territories. These are mainly the same as the countries’ ISO 3166 codes, but there are some exceptions (mainly when country names changed).
• generic top-level domains (gTLDs), three-or-more-letter domain names that were designed to represent different categories or classes of organizations. Most gTLDs are unrestricted, but not all. There are sponsored and unsponsored gTLDS.
• infrastructure top-level domains (iTLDs), the four-letter domain name .arpa is the only one in use currently.

In the Beginning

In 1985, the first 6 of the gTLDs were created. They were as follows:

• .com for commercial organizations
• .edu for post-secondary educational organizations
• .gov for government organizations
• .mil for military organizations in the United States
• .net for network infrastructures
• .org for organizations that didn’t fall into the other categories

.com

Among the early adopters of the .com TLD were Xerox Corporation, Hewlett-Packard, IBM, Intel, ATT, Bell-Atlantic, and GE. Although it was originally intended to identify commercial entities, the restriction was lifted in the mid-1990s, and .com is now the largest TLD.

.edu

Originally intended to be limited to post-secondary institutions worldwide, unlike .com, .edu became more restricted as time passed. Some early registrants, including some high schools, museums, and the Folger Shakespeare Library, still have an .edu TLD, but new registrants must meet the criteria.

.gov

While in other countries, government addresses are designated in second-level domains, in the US, .gov is a TLD, although some organizations have chosen to use .fed instead, and the Department of Defense has chosen to use .mil, and US Postal Service uses .com. The .gov TLD can only be used by government entities. States use their full name or postal abbreviation.

.mil

This TLD distinguishes the Department of Defense and its subsidiaries from the rest of the US government. As for .gov, the US is the only country with a TLD for the military: other countries generally use a second-level domain.

.net

Originally intended to designate network providers such as Internet Service Providers (ISPs), .net has in practice been adopted without restriction and is one of the top TLDs.

.org

Originally recommended for individuals and organizations that didn’t meet the criteria for the other 5 original gTLDs, .org is often, but not always, the choice of non-profit organizations and political parties.

New Developments

Authorization of seven new gTLDs, available for use by 2004, broadened the possibilities. They are:

• .aero for the air transport industry
• .biz for businesses
• .coop for cooperatives
• .info for informational sites (unrestricted)
• .museum for museums
• .name for individuals and families
• .pro for professionals including certified pubic accountants, lawyers, and physicians.