Generic Top-Level Domains (gTLDs) are one of the categories of Top-Level Domains (TLDs) maintained by the Internet Assigned Numbers Authority (IANA) for use in the Internet's domain name system. A top-level domain is the last level of every fully qualified domain name. They are called "generic" for historical reasons; initially, they were contrasted with country-specific TLDs outlined in RFC 920.
The commonly known domain names can end with two letters, such as .tw, .cn, .hk, which are called Country Code Top-Level Domains (ccTLDs), or with three or more letters, such as .com, .net, .org, .info, and these are known as Generic Top-Level Domains (gTLDs).
There are seven original generic top-level domains, which are often referred to as international domain names. Since the Internet originated in the United States, the earliest domain names had no country identifier, and they were categorized by purpose into several classes, each with a different suffix: .com (for commercial businesses); .net (for network services); .org (for organizations, associations, etc.); .gov (for government departments); .edu (for educational institutions); .mil (for the military); .int (for international organizations). Initially, the domain name system was primarily for use within the United States, hence businesses, institutions, and government departments in the U.S. used these "international domain names." As the Internet developed globally, domains like .edu, .gov, and .mil were generally reserved for U.S. use, while the other commonly used domains like .com, .org, and .net became universal, and thus these domain names are often referred to as "international domain names" and are still used by countries around the world.
Additionally, domains such as .name and .pro are considered generic domains; however, these domains are designated as restricted domains because registering within them requires proof of eligibility according to guidelines set for each domain.
Historically, the group of generic top-level domains included those created during the early development of the domain name system and are now sponsored by designated agencies or organizations, restricted for use by certain types of registrants. Therefore, domains like .edu, .gov, .int, and .mil are now considered sponsored top-level domains, similar to other thematic top-level domains like .jobs. The entire group of domains without geographic or national designation is still commonly referred to as generic top-level domains.
Internet users are familiar with generic top-level domains like .com, .org, .net, or .info, which, as of 2011, numbered only 22 globally, and they are part of the structure of the Internet's domain name system.
What are the new generic top-level domains?
As the inventory of traditional international top-level domains like .com became increasingly scarce, those wishing to launch websites with attractive domain names have had to turn to new generic top-level domains in order to register good quality domain names.
In November 2000, the Internet Corporation for Assigned Names and Numbers (ICANN) approved seven new generic top-level domains (gTLDs), including .biz (restricted to businesses), .info (open to all websites), .name (for individual registration), .pro (limited to licensed professionals, including lawyers, doctors, and accountants), .aero (for all websites related to air transport), .museum (for museums), and .coop (for cooperative enterprises). These seven new gTLDs were selected from a pool of 40 candidate domains. ICANN is currently negotiating registration issues with the selected gTLD applicants. Proponents of adding new gTLDs claim that these new domains will easily create and free up space for Internet addresses. Opponents argue that too many gTLDs could lead to confusion and potentially increase the likelihood of trademark infringement, profiteering from trademarks, or trademark squatting. ICANN has approved the registration of several organizational domains but has not yet approved any new gTLD registrations.
On June 20, 2011, ICANN officially passed the New gTLD program at a meeting in Singapore, allowing any company or organization the right to apply for new top-level domains. As of now, there are thousands of top-level domains, including highly distinctive suffixes such as .xyz, .top, .wang, .club, .city, .berlin, .nyc, and others, creating possibilities for a more diverse range of future Internet addresses.