The exchange of information among dns servers regarding configured zones is known as "zone transfer".
DNS zone transfer, is a kind of DNS transaction. It is one of the numerous instruments accessible for managers to duplicate DNS databases over an arrangement of DNS servers.
A zone transfer utilizes the Transmission Control Protocol (TCP) for transport, and appears as a client– server exchange. The customer asking for a zone exchange might be a slave server or optional server, asking for information from an ace server, in some cases called an essential server. The part of the database that is duplicated is a zone.