Top-level domain
Also called: TLD or top-level domain
A top-level domain (TLD) is a domain name on the Internet at the highest level of the DNS system. Well-known top-level domains are .com, .org, .nl and .be. Within top-level domains, unique domain names are issued by managing organizations designated by IANA, part of ICANN. Top-level domain names make it possible to request websites and create and use e-mail addresses, among other things.
After successfully claiming a unique name within a top-level domain, the owner can specify through the DNS system to which server(s) the domain name should point. Unlimited subdomains can be created under a domain name by the owner if desired, which can point to other server(s) and/or separate sites as desired.
Differences between TLDs
The term top-level domain officially refers only to the extension. In practice, the term also refers to domain names registered within a top-level domain. In fact, these are second-level domains.
Top-level domains can be divided into a number of categories. The best known and most important distinction is between generic top-level domains (gTLD, generic international domain names of at least three characters) and country-code top-level domains(ccTLD, domain names with a two-character extension intended for a particular country or territory). In addition, some special top-level domains exist for technical purposes, such as test and localhost.
Available domain names
The fact that within a top-level domain each name can only be registered once means that popular and interesting domain names are scarce. For a long time, the ability to register domain names was limited to a limited number of gTLDs and ccTLDs. Since 2011, it has been possible to apply to manage a new TLD yourself. This has led to the arrival of many new TLDs managed by or on behalf of governments (such as .frl and .vlaanderen) and companies (such as .biz, .aero and .google).
Some TLDs divide domain names into different categories. For example, the United Kingdom has separate exits within the .uk domain for businesses (.co.uk) and government organizations (.org.uk).
TLDs may have special conditions attached to them. For example, protected or offensive names may be excluded from registration. Some extensions reserved for certain types of institutions, such as education (.edu) and government (.gov). Their use is mainly limited to the United States.
