The Domain Name System (DNS) translates human-friendly names like example.com into the IP addresses that computers actually use. It is often described as the phone book of the internet.
When you visit a site, your resolver queries a chain of servers: root servers, TLD servers (like .com), and finally the authoritative nameserver for the domain, which returns the address.
DNS records have types: A and AAAA for addresses, MX for mail servers, NS for nameservers, TXT for text (including SPF and DKIM), and more. Our DNS Lookup tool queries all of these over HTTPS through public resolvers.