as one who is NOT affiliated with ISC Bind named program but actually read a lot on DNS and wrote user configuration front-end providing closed-net DNSSEC, hidd

as one who is NOT affiliated with ISC Bind named program but actually read a lot on DNS and wrote user configuration front-end providing closed-net DNSSEC, hidden master, bastion, split-horizon, and private root server settings to named.conf and its zone (text-based) database files, my take of the definition of nameserver and DNS resolver is this: nameserver is a term used by DHCP and host resolver to be the server that provides a fully resolved (one that did all the resolving or asked others to do some resolving) upon receiving a DNS request before sending the final answer to the requestor (often the host via resolver library (as often guided by /etc/resolve.conf). The nameserver can be a forwarder and by its stated function not have a recursive mechanism. Nameserver is more about the first step for a host to obtain an answer to its query. DNS resolver is not the common term to use but refers to a generic DNS server configured to do a partial or full recursive (depending on whether they also have some primary zone(s) locally) with a goal to contact an authoritative server for each zone (parts of the domain name separated by a period). A DNS resolver would not necessarily be the first server that a host would request. Of course, caching might provide one of its zone answer sooner, if enabled and encountered an answer previously within its expiration period. Any error, typos, mistakes are mine and mine alone. This is my off-the-cuff answer.