DoH improves privacy by hiding domain name lookups from anyone lurking on public Wi-Fi, your ISP or others on your local network. Learn more.
support.mozilla.org
DoH! Firefox Engages More Secure DNS Over HTTPS Protocol — Here’s What That Means for You
https://www.thesslstore.com/blog/doh-firefox-engages-more-secure-dns-over-https-protocol-heres-what-that-means-for-you/