The SOA is the specific record type found in every zone and contains information that identifies the sever primarily responsible for the zone as well as some operational properties for the zone.
Explanation:
The Start of Authority Records (SOA) has the following information they are
Serial Number: This number is used to find when zonal information should be replicated.
Responsible person: The Email address of a person is responsible for managing the zone.
Refresh Interval: It specifies how often a secondary DNS server tries to renew its zone information.
Retry Interval: It specifies the amount of time a secondary server waits before retrying the zone information has failed.
Expires After: IT specifies the amount of time before a secondary server considers its zone data if it can't contact with the primary server.
Minimum TTL: It specifies the default TTL value for a zone data when a TTL is not supplied.
