Top-Level Domain (TLD)

Definition of a Top-Level Domain and Examples of Common Domain Extensions

Image of '.com' superimposed over computer circuitry
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The top-level domain (TLD), sometimes called the internet domain extension, is the very last section of an internet domain name, located after the last dot, to help form a fully qualified domain name ( FQDN).

For example, the top-level domain of lifewire.com and google.com are both .com.

What Is the Purpose of a Top-Level Domain?

Top-level domains serve as an instant way to understand what a website is about or where it's based.

For example, seeing a .gov address, like in www.whitehouse.gov, will immediately inform you that the material on the website is centered around government. 

A top-level domain of .ca in www.cbc.ca indicates something about that website, in this case, that the registrant is a Canadian organization.

What Are the Different Top-Level Domains?

A number of top-level domains exist, many of which you've probably seen before.

Some top-level domains are open for any person or business to register, while others require that certain criteria be met.

Top-level domains are categorized in groups: generic top-level domains (gTLD)country-code top-level domains (ccTLD)infrastructure top-level domain (arpa), and internationalized top-level domains (IDNs).

Generic Top-level Domains (gTLDs)

Generic top-level domains are the common domain names you're likely most familiar with. These are open for anyone to register domain names under:

  • .com (commercial)
  • .org (organization)
  • .net (network)
  • .name (name)
  • .biz (business)
  • .info (information)

Additional gTLDs are available that are called sponsored top-level domains, and are considered restricted because certain guidelines must be met before they can be registered:

  • .int (international): Used by international organizations for treaty-related purposes, and requires a United Nations registration number
  • .edu (education): Limited to educational institutions only
  • .gov (government): Limited to U.S. governmental entities only
  • .mil (military):  Limited to the U.S. military only
  • .jobs (employment): Must be registered under the legal name of a company or organization
  • .mobi (mobile): Might have to adhere to mobile-compatible guidelines
  • .tel (Telnic): Limited to hosting related to contact information, not websites

Country Code Top-level Domains (ccTLD)

Countries and territories have a top-level domain name available that's based on the country's two-letter ISO code. Here are some examples of popular country code top-level domains:

  • .us: United States
  • .ca: Canada
  • .nl: Netherlands
  • .de: Germany
  • .fr: France
  • .ch: Switzerland
  • .cn: China
  • .in: India
  • .ru: Russia
  • .mx: Mexico
  • .jp: Japan
  • .br: Brazil

The official, exhaustive list of every generic top-level domain and country code top-level domain is listed by the Internet Assigned Numbers Authority (IANA).

Infrastructure Top-Level Domains (arpa)

This top-level domain stands for Address and Routing Parameter Area and is used solely for technical infrastructure purposes, such as resolving a hostname from a given IP address.

Internationalized Top-Level Domains (IDNs)

Internationalized top-level domains are top-level domains that are displayed in a language-native alphabet.

For example, .рф is the internationalized top-level domain for the Russian Federation.

How Do You Register a Domain Name?

Internet Corporation for Assigned Names and Numbers (ICANN) is in charge of managing top-level domains, but registration can be done through a number of registrars.

Some popular domain registrars you may have heard of include GoDaddy, 1&1, NetworkSolutions, and Namecheap.