For implementation in Fedora 33 , which forces the distribution to use systemd-resolved by default for resolving DNS queries. Glibc will be migrated to nss-resolve from the systemd project instead of the built-in NSS module nss-dns.
Systemd-resolved performs functions such as maintaining settings in the resolv.conf file based on DHCP data and static DNS configuration for network interfaces, supports DNSSEC and LLMNR (Link Local Multicast Name Resolution). Among the advantages of switching to systemd-resolved is support for DNS over TLS, the ability to enable local caching of DNS queries, and support for binding different handlers to different network interfaces (depending on the network interface, a DNS server is selected to access, for example, for VPN interfaces DNS queries will be sent via VPN). DNSSEC is not planned for Fedora (systemd-resolved will be built with the DNSSEC=no flag).
Systemd-resolved has already been used by default in Ubuntu since the 16.10 release, but integration will be different in Fedora - Ubuntu continues to use the traditional nss-dns from glibc, i.e. glibc continues to process /etc/resolv.conf while Fedora is scheduled to replace nss-dns with systemd's nss-resolve. For those who do not want to use systemd-resolved, there will be an option to disable it (you need to deactivate the systemd-resolved.service and restart NetworkManager, which will create the traditional /etc/resolv.conf).
Source: opennet.ru