Recursive DNS Resolver
A recursive DNS resolver is a server that accepts [[dns|DNS]] queries from clients and performs the full resolution process on their behalf, walking the DNS hierarchy from the [[dns-root-server|root nameservers]] down to the [[authoritative-dns|authoritative server]] for the queried domain. Unlike an [[authoritative-dns|authoritative server]], a recursive resolver is a middleman: it caches responses according to each record's [[ttl|TTL]], reducing latency and upstream query load. ISP-operated resolvers, public services like Cloudflare 1.1.1.1 and Google 8.8.8.8, and corporate DNS servers all function as recursive resolvers. [[dns-over-https|DNS over HTTPS]] and [[dns-over-tls|DNS over TLS]] encrypt the channel between client and recursive resolver to prevent eavesdropping.
Example
When you visit example.com, your laptop sends a query to the recursive resolver at 1.1.1.1, which contacts root, .com TLD, and authoritative nameservers in sequence before returning the IP — subsequent users hitting 1.1.1.1 receive the cached answer instantly.