Zone file

In computer networking, a zone file is a database element of the domain name system (DNS) originally used by the Berkeley Internet Name Domain (BIND) software package and other DNS server software. As such it has derived its definition from the structure of the input data of the BIND program. A zone file typically contains information] that defines mappings between [[domain names and IP addresses and other resources, organized in form of so-called zone resource records (RR).

Resolving a name into a numeric resource is often called a 'forward' map using a forward-zone file, and the reverse map, translating an address into a name uses reverse-zone files. A zone is the portion of a domain or the entire DNS name space of which management has been delegated. This applies at all levels of top-level domains and subdomains. The zone file is the database representation of such delegation. The format of the zone file is defined in RFC 1035 as well as the documentation for BIND.