Firefox begins rollout of the encrypted DNS Over HTTPS (DoH) feature. By this time, DNS over HTTPS (DoH) is enabled by default for US-based users only, but that will change in the future.
How to enable DNS over HTTPS in Firefox
DNS-over-HTTPS is a relatively young web protocol, implement about two years ago. It is intended to increase user privacy and security by preventing eavesdropping and manipulation of DNS data by man-in-the-middle attacks by using the HTTPS protocol to encrypt the data between the DoH client and the DoH-based DNS resolver. Here is how you can enable it in Mozilla Firefox.