This page is available in

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.

Do you have feedback on the definitions or the terms? Send us an email to:


  • anycast instance

    A server that responds to an anycast Internet Protocol (IP) address. With anycast routing, a server is replicated across multiple network locations. The servers are then assigned to the same anycast IP address. Each server assigned to that IP address is referred to as an anycast instance (or simply an instance). When a computer sends a message to an anycast IP address, Internet routers automatically direct the message to the nearest (in terms of routing distance) available instance of that server. Anycast routing helps reduce latency and improve reliability.

    Many of the authoritative name servers in the Domain Name System use anycast routing.