A zone file contains the following lines:and is included in the BIND configuration using this...

A zone file is a text file that defines a portion of the DNS namespace, called a zone. A zone file contains resource records that map domain names to IP addresses or other information. A zone file must follow the rules of the DNS hierarchy, which means that it can only contain records for names that are within the zone’s domain. For example, a zone file for example.com can only contain records for names that end with example.com, such as www.example.com or mail.example.com. It cannot contain records for names that are outside the zone’s domain, such as google.com or example.net. This is because the DNS server that hosts the zone file is only authoritative for the zone’s domain, and not for any other domains. If a zone file contains records for names that are outside the zone’s hierarchy, it will cause errors and inconsistencies in the DNS resolution process.  References: LPIC-2 202 exam objectives, DNS zone file format, DNS hierarchy