In the context of information retrieval, particularly in domains like DNS (Domain Name System), the terms "authoritative" and "non-authoritative" refer to the source of the information provided.
Authoritative Answer:
- An authoritative answer comes from a source that has the original data or is responsible for the data. For example, a DNS server that holds the original records for a domain is considered authoritative for that domain. When it provides an answer, it is considered reliable and definitive.
Non-Authoritative Answer:
- A non-authoritative answer is provided by a source that does not have the original data but may have cached it from an authoritative source. For instance, if a DNS resolver queries an authoritative DNS server and then provides that information to another client, the response is non-authoritative because the resolver is not the original source of the data.
In summary, authoritative answers are from the original source, while non-authoritative answers are from intermediaries that may not have the original data.
