DNS zone file
DNS zone file, also known as the master file (RFC 1035), is a simple text file that defines a particular DNS zone by including all DNS resource records (RR) for that zone. This DNS zone file is located on the primary name server. Any changes to the domain name are performed at the primary DNS zone that is located in the primary name server. They are modifications to the DNS zone files. Adding or removing DNS RR will change the content of the zone file.