An SOA(Start of Authority) Record is the most essential part of a Zone file. The SOA record is a way for the Domain Administrator to give out simple information about the domain like, how often it is updated, when it was last updated, when to check back for more info, what is the admins email address and so on. A Zone file can contain only one SOA Record.
A properly optimized and updated SOA record can reduce bandwidth between nameservers, increase the speed of website access and ensure the site is alive even when the primary DNS server is down.
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