DNS records are instructions stored on authoritative DNS servers that control how traffic is routed for a domain. A records map domains to IPv4 addresses, MX records specify mail servers, TXT records carry verification strings (SPF, DKIM, etc.), and NS records delegate a domain to specific name servers. Without correct DNS records, emails fail, websites become unreachable, and SSL certificates cannot be issued.
Traditional DNS queries are sent in plain text, making them visible to ISPs and potential attackers. Cloudflare's DoH API (1.1.1.1) encrypts every query over HTTPS, preventing eavesdropping and manipulation. It is also one of the fastest resolvers globally, typically returning results in under 10 ms.
TTL (Time To Live) is the number of seconds that resolvers and browsers may cache a DNS record. A TTL of 3600 means downstream caches keep the record for up to one hour. When you change a DNS record, the old value remains in caches until the TTL expires, so lower TTLs (e.g. 300) allow faster propagation during migrations, while higher TTLs reduce query load in steady state.