Disclaimer: If you do now know what DNS is, you may skip this article.
DNSSEC (Domain Name System Security Extension) is a protocol, which adds authentication mechanism to DNS. It works by adding signatures to DNS records, allowing clients to verify name servers. This is to protect user against DNS poisoning and MITM attack.
How it works - https://www.cloudflare.com/dnssec/how-dnssec-works/
