A Look at the Most Common Top Level Domains

A top-level domain is one of the domains at the top of the hierarchical Domain Name System used on the internet. The most common top-level domain you're familiar with is almost certainly .com. To understand the concept of TLDs and domain extensions requires a brief explanation of internet domains in general.

Internet Domain Names

A domain name is a string used to name websites and other servers on computer networks.

On the internet, these strings are managed by the Domain Name System. The DNS uses a system of multi-level strings separated by periods to organize domain names.

Most websites use more than one level of naming, listed in order from lowest to highest when reading from left to right. They often include second-level domain names and subdomain names. The top-level domain appears last.

Generic Top-Level Domain Extensions

Although .com is the most commonly used top-level domain extension on the internet, many others exist. These six TLDs were part of the original internet specifications for domain extensions:

.edu (education)
.gov (government)
.int (international)
.mil (military)
.net (network)
.org (organization)

Many new TLDs have been deployed on the internet in recent years. Some of these are intended for broad use worldwide, while others are designed to serve special interest groups. Although they are not as popular as the original TLDs, you may also encounter some of these newer domain extensions when browsing the web:

.biz
.info
.jobs
.mobi
.name
.tel

The ICANN organization ultimately oversees the process of managing internet domains including any new TLD extensions.

Top-Level Country-Code Domain Extensions

Besides the generic TLDs, the Internet also maintains domain extensions for each country to help organize websites within each nation.

These extensions are named according to worldwide standard two-letter country codes similar to those used by the postal system. Examples of country code TLDs include: