The top-level domain (TLD) represents the last segment of a domain name – the part that follows immediately after the last dot in the domain name. For instance, in a website address like www.google.com, “.com” is a TLD. The Internet Corporation for Assigned Names and Numbers (ICANN) manages these domain endings. Examples of common top-level domains include .com, .org, .net, and codes corresponding to countries like .uk, .us, and .au.
Now, regarding “YOUTUBE” as a TLD, it is important to clarify that “YOUTUBE” is not technically a TLD. Rather, it’s a second-level domain under the “.com” TLD.
TLDs are typically categorized into two broad categories: generic top-level domains (gTLDs) and country code top-level domains (ccTLDs). The “.com” in “www.youtube.com” is actually a gTLD, which is typically used by commercial organizations. ICANN lists this and many other gTLDs in its database, as conveyed by the CircleID’s reference article “List of Top-Level Domains” (2015).
“YOUTUBE” is not a TLD but it does exist as a registered domain under the “.com” TLD. Google owns the domain “youtube.com”, as the WHOIS records in ICANN’s database show. The company has been the proprietor of the address since 2005, which it uses for its widely popular video-sharing platform.
The term “youtube” only becomes a TLD if a preceding domain name is added to it (for instance, “videos.youtube”). It is still only a top-level domain for the preceding second-level domain, i.e., “videos”, (making “videos.youtube” a fully qualified domain name (FQDN)) but on its own, “youtube” remains a second-level domain under the “.com” TLD.
In other words, in the domain name “www.youtube.com”, “com” represents the TLD, “youtube” the second-level domain (SLD), and “www” the third-level domain (usually referred to as a subdomain). This hierarchical structure of domain names is recorded by the Domain Name System (DNS), as explained in “Internet Domain Names: Background and Policy Issues” (Kruger, 2012).
Taking all these into consideration, it can be firmly established that “YOUTUBE” is not an existing top-level domain as ICANN has no record of a “.youtube” TLD. ICANN’s rules limit the creation and use of top-level domains mainly to maintain internet stability and security, according to “Domain Name System (DNS) Security, Stability, Resiliency, and Interoperability.” (ICANN, 2013)
Sources:
1. CircleID (2015): “List of Top-Level Domains”.
2. Kruger L., (2012): “Internet Domain Names: Background and Policy Issues”.
3. ICANN (2013): “Domain Name System (DNS) Security, Stability, Resiliency, and Interoperability.”
4. ICANN WHOIS database.
