In the Internet, a domain name is a string that identifies a realm of administrative autonomy, authority or control. Domain names are often used to identify services provided through the Internet, such as websites, email services and more. As of 2017, 330.6 million domain names had been registered. Domain names are used in various networking contexts and for application-specific naming and addressing purposes. In general, a domain name identifies a network domain or an Internet Protocol (IP) resource, such as a personal computer used to access the Internet, or a server computer.
.us is the Internet country code top-level domain (ccTLD) for the United States. It was established in early 1985. Registrants of .us domains must be U.S. citizens, residents, or organizations – or foreign entities with a presence in the United States or any territory of the United States. Most registrants in the U.S. have registered for .com, .net, .org and other gTLDs, instead of .us, which has primarily been used by state and local governments, even though private entities may also register .us domains.
.ca is the Internet country code top-level domain (ccTLD) for Canada. The domain name registry that operates it is the Canadian Internet Registration Authority (CIRA).
.ee is the internet country code top-level domain (ccTLD) of Estonia, operated by the Estonian Internet Foundation.
.ie is the country code top-level domain (ccTLD) which corresponds with the ISO 3166-1 alpha-2 code for Ireland. The Internet Assigned Numbers Authority (IANA) list the Computing Services Computer Centre of University College Dublin as its sponsoring organisation for the .ie domain. Since 2000 the business of administrating the domain registry has been handled by IE Domain Registry Limited. Domain name registration is open to individuals located in, or with a significant connection with, any part of the island of Ireland.
A country code top-level domain (ccTLD) is an Internet top-level domain generally used or reserved for a country, sovereign state, or dependent territory identified with a country code. All ASCII ccTLD identifiers are two letters long, and all two-letter top-level domains are ccTLDs.
.ae is the country code top-level domain (ccTLD) in the Domain Name System of the Internet for the United Arab Emirates. It is administered by .aeDA which is part of the Telecommunications and Digital Government Regulatory Authority of UAE (TDRA).
.ai is the Internet country code top-level domain (ccTLD) for Anguilla, a British Overseas Territory in the Caribbean. It is administered by the government of Anguilla.
.aq is the Internet country code top-level domain (ccTLD) for Antarctica. It is derived from the French Antarctique and is reserved for organizations that work in Antarctica or promote the Antarctic and Southern Ocean regions. It is administered by Peter Mott of Antarctica Network Information Centre Limited from Christchurch, New Zealand.
.bb is the Internet country code top-level domain (ccTLD) for Barbados.
.bj is the Internet country code top-level domain (ccTLD) for Benin. It is administered by the Office of Stations and Telecommunications of Benin. Despite having no "j" in its name in any of its official languages, Benin was allocated .bj as the other possible codes .be, .bn, and .bi had already been allocated to other entities.
.bw is the Internet country code top-level domain (ccTLD) for Botswana. It is officially administered by the Botswana Communication Regulatory Authority since 2013, previously being administered by the University of Botswana.
.tl is the current country code top-level domain (ccTLD) for East Timor (Timor-Leste). It is administered through the Council of Country Code Administrators (CoCCA) and second-level registration is available through resellers worldwide with no local presence requirement.
.tw is the Internet country code top-level domain (ccTLD) for Taiwan. The domain name is based on the ISO 3166-1 alpha-2 country code TW. The registry is maintained by the Taiwan Network Information Center (TWNIC), a Taiwanese non-profit organization appointed by the National Communications Commission (NCC) and the Ministry of Transportation and Communication. Since 1 March 2001, TWNIC has stopped allowing itself to sign up new domain names directly, instead allowing new registration through its contracted reseller registrars. As of May 2023, there are 17 registrars.
.in is the Internet country code top-level domain (ccTLD) for India. It was made available in 1989, four years after original generic top-level domains such as .com, .net and the country code like .us. It is currently administered by the National Internet Exchange of India (NIXI).
.mx is the Internet country code top-level domain (ccTLD) for Mexico, which in 2009 was re-opened to new registrations by NIC México. In 2009, the .mx ccTLD was rolled out in three steps:
.so is the internet country code top-level domain (ccTLD) for Somalia. After a long absence, the .so domain was officially relaunched on November 1, 2010, by .SO Registry, which is regulated by the nation's Ministry of Posts and Telecommunications. It was launched through various accredited registrars around the world.
.mv is the Internet country code top-level domain (ccTLD) for the Republic of Maldives. It is administered by Dhiraagu Pvt Ltd, a telecommunications company.
.nc is the Internet country code top-level domain (ccTLD) for New Caledonia. Registry operations are managed by the Office des postes et télécommunications.
.বাংলা is a secondary and internationalized country code top-level domain (ccTLD) on the Internet for Bangladesh. This domain is meant for web addresses in the Bengali language. It is administered by the Ministry of Posts, Telecommunications and Information Technology.
Bangladesh 
