A public recursive name server (also called public DNS resolver) is a name server service that networked computers may use for query to DNS, the decentralized Internet naming system, in place of or in addition to name servers operated by the Internet service provider to which the devices are connected.
Below is a list of public DNS service operators.
Quad9 is a not-for-profit public-benefit organization supported by IBM, Packet Clearing House (PCH), Global Cyber Alliance (GCA), and many other cybersecurity organizations for the purpose of operating a privacy-and-security-centric public DNS resolver. Its main differentiators from other DNS resolvers are that it does not record the queries users send to it, and that it automatically blocks domains known to be associated with malicious activity. Quad9 offers DNS over TLS service over port 853, DNS over HTTPS over port 443 and DNSCrypt service over port 443. - Wikipedia
DNS over TLS
DNS over HTTPS