Recommended Free Tools
iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
A second-level domain is the label directly before a top-level domain (TLD). In example.com, example is the second-level label and .com is the TLD. The phrase can also refer to the full name example.com, so context matters.
How domain levels work
Domain names are hierarchical: their labels are separated by dots, and each label’s level is identified by its position. The TLD is the final named level. The second-level label sits immediately to its left.
ICANN’s glossary defines a second-level domain as “A label that is found in a zone that is under a top-level domain.” ICANN glossary
The Tool Desk
Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Identify each part of a domain name
orgis the TLD inicann.org.icannis the second-level label: it appears immediately before the TLD.whoisis a further label inwhois.icann.org, commonly described as a third-level label or subdomain.
ICANN uses this same breakdown for whois.icann.org: org is the top-level level, icann the second-level, and whois the third-level. ICANN: What is a domain name?
#1 Best Overall
Does “second-level domain” mean a label or a full name?
In precise DNS terminology, a second-level domain is the label beneath a TLD—for example, icann. In general usage, the phrase may refer to the full second-level name, such as icann.org. ICANN’s FAQ calls the portion before the TLD the “second-level domain name” and gives icann in icann.org as its example. ICANN FAQ
To avoid ambiguity, specify whether you mean the label alone or the whole name. For example: “icann is the second-level label in the name icann.org.”
How it differs from a subdomain
A subdomain is an additional label placed before the second-level name. In whois.icann.org, whois is the additional label, while icann.org remains the second-level name. The additional label does not change which part is immediately beneath the TLD.
Do these 3 things before closing this tab:
1Scan for outdated or missing drivers - takes under a minute2Clear out junk files and repair common Windows errors3Fix the driver behind crashes, sound loss and screen glitchesQuick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
