Top-Level Domain (TLD)
Definition - What does Top-Level Domain (TLD) mean?
Top-level domain (TLD) refers to the last segment of a domain name, or the part that follows immediately after the "dot" symbol. TLDs are mainly classified into two categories: generic TLDs and country-specific TLDs. Examples of some of the popular TLDs include .com, .org, .net, .gov, .biz and .edu. The Internet Corporation for Assigned Names and Numbers (ICANN), is the entity that coordinates domains and IP addresses for the internet.
Historically, TLDs represented the purpose and type of domain. ICANN has generally been very strict about opening up new TLDs, but in 2010, it decided to allow the creation of numerous new generic TLDs as well as TLDs for company-specific trademarks.
Top-level domains are also known as domain suffixes.
Techopedia explains Top-Level Domain (TLD)
A top-level domain recognizes a certain element regarding the associated website, such as its objective (business, government, education), its owner, or the geographical area from which it originated. Each TLD includes an independent registry controlled by a specific organization, which is managed under the guidance of the Internet Corporation for Assigned Names and Numbers (ICANN).
ICANN recognizes the following types of TLDs:
- Generic Top-Level Domains (gTLD): These are the most popular types of TDLs. Some examples include ".edu" for educational sites and ."com" for commercial sites. These types of TLDs are available for registration.
- Country-Code Top-Level Domains (ccTLD): Every ccTLD recognizes a specific country and is generally two letters long. For example, the ccTLD for Australia is ".au".
- Sponsored Top-Level Domains (sTLD): These TLDs are supervised by private organizations.
- Infrastructure Top-Level Domains: There is only one TLD in this category, which is ".arpa". The Internet Assigned Numbers Authority controls this TLD for the Internet Engineering Task Force (IETF).
Some of the TLDs and their explanations are as follows:
- .com - Commercial businesses
- .org - Organizations (generally charitable)
- .net - Network organizations
- .gov - U.S. government agencies
- .mil - Military
- .edu - Educational facilities like universities
- .th - Thailand
- .ca - Canada
- .au - Australia
According to the IETF, there are four top-level domain names that are reserved, and are not used in production networks inside the worldwide domain name system:
- .example - Only available to use in examples
- .invalid - Only available to use in invalid domain names
- .localhost - Only available to use in local computers
- .test - Only available to use in tests