The “.zone” is a generic top-level domain (gTLD) in the Domain Name System (DNS) of the Internet. DNS, which acts as a directory for internet names, uses different types of TLDs (Top-Level Domains) for differentiating services, countries, and organizations. Traditional TLDs include .com, .org and .net, plus there’s a long list of country-specific ones (like .us, .de, and .jp).
However, in a bid to increase competition and choice in the domain name market, ICANN (the Internet Corporation for Assigned Names and Numbers) officially started the process of taking applications from organizations that would like to create and manage their own gTLDs in 2012.
One of the gTLDs introduced in this phase is the .zone domain. It is operated by the Donuts registry, which currently manages hundreds of other gTLDs. The .zone TLD was delegated to the Root Zone of the DNS on the 5th of March, 2014, which signifies that Donuts completed all the necessary technical and administrative tasks necessary for the .zone TLD to be fully operational.
The “.zone” domain is labeled as a “generic” TLD under ICANN’s domain name classification. This means it can be used by anyone for any purpose. This gives it a considerable amount of flexibility – it can represent geographical locations, a state of being (e.g., “in the zone”), or a specific topic or industry (for instance, the gaming zone or the tech zone).
Although there are no technical requirements specifically linked to the .zone TLD, domain names registered under this TLD need to adhere to the standard protocols for DNS operation. This includes adherence to technical standards and specifications set forth in numerous RFC documents (a series of publications which describe the protocols and policies of Internet functionality), including but not limited to RFCs 1034, 1035, and 1123.
In terms of examples, one can look at domains like event.zone, a platform for event planning, or crypto.zone, which deals with cryptocurrency.
The sources used to construct this answer include the Official ICANN Website, IANA Root Zone Database, and the official Donuts Inc. website. Further technical descriptions and domain standards were referred from the Standard for the Format of ARPA Internet Text messages (RFC 822) and Domain Names – Concepts and Facilities (RFC 1034 and RFC 1035).
References:
1. ICANN.org
2. IANA.org
3. Donuts.Domains
4. Tools.ietf.org (RFC documents)