This refers to the DNS servers that have been registered at the InterNIC as the authorities for an Internet (DNS) domain. These name servers maintain the definitive information about a domain, such as where to send mail to users in the domain, where the domain's web server is, etc. All other name servers can only provide non-authoritative answers (that is, answers from their cache). If you do not know which servers are the registered authorities for your Internet domain, you can either ask your ISP, or refer to our online procedure to find out for yourself.