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ICANN Acronyms and Terms

ICANN has hundreds of acronyms and terms, which can be confusing. We created this multilingual tool to help explain what these terms mean and facilitate your work within the ICANN community. Search for terms by name or acronym using the search bar, or search by letter. All acronyms and terms are available in Arabic, Chinese, French, Russian, and Spanish.

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  • subdomain

    A domain that resides within a higher-level domain in the Domain Name System hierarchy. For example, the domains and are subdomains of the second-level domain The domain is a subdomain of the top-level domain .org.

    Subdomains can be delegated to specific entities. Registrars, for example, delegate second-level domains to registrants. The registrants can then delegate subdomains within their second-level domains.