mjhjmtu

It seems that on newer Linux systems you can no longer check the DNSs by doing cat /etc/resolv.conf. It is now done by systemd-resolve --status.

Below is an example output of that command:

user@user:~$ systemd-resolve --status
Global
 DNSSEC NTA: 10.in-addr.arpa
 16.172.in-addr.arpa
 168.192.in-addr.arpa
 17.172.in-addr.arpa
 18.172.in-addr.arpa
 19.172.in-addr.arpa
 20.172.in-addr.arpa
 21.172.in-addr.arpa
 22.172.in-addr.arpa
 23.172.in-addr.arpa
 24.172.in-addr.arpa
 25.172.in-addr.arpa
 26.172.in-addr.arpa
 27.172.in-addr.arpa
 28.172.in-addr.arpa
 29.172.in-addr.arpa
 30.172.in-addr.arpa
 31.172.in-addr.arpa
 corp
 d.f.ip6.arpa
 home
 internal
 intranet
 lan
 local
 private
 test

Link 3 (wlp4s0)
 Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6
 LLMNR setting: yes
MulticastDNS setting: no
 DNSSEC setting: no
 DNSSEC supported: no
 DNS Servers: fe80::e695:6eff:fe40:9af2
 DNS Domain: lan

The description states:

--status

Shows the global and per-link DNS settings in currently in effect.

What does the Global section represent, what to those addresses represent and how are they related to DNSs?

The systemd-resolve documentation says:

The DNS servers contacted are determined from the global settings in
/etc/systemd/resolved.conf, the per-link static settings in
/etc/systemd/network/*.network files, the per-link dynamic settings
received over DHCP and any DNS server information made available by
other system services.

It think this explains your Global flag.

DNSSEC NTA stands for DNSSEC Negative Trust Anchor. This applies to domains that are not signed or not correctly signed to "override" DNSSEC data, by disabling DNS validation for the specific domain. See RFC7646, which I quote:

NTAs are configured locally on a validating DNS recursive resolver
to shield end users from DNSSEC-related authoritative name server
operational errors. NTAs are intended to be temporary and only
implemented by the organization requiring an NTA (and not
distributed by any organizations outside of the administrative
boundary).