What is DNS?
Answer
DNS (Domain Name System) is the Internet's "phone book" — it translates human-readable domain names (like google.com) into machine-readable IP addresses (like 142.250.80.46). Without DNS, users would need to memorize IP addresses for every website. DNS is a distributed, hierarchical system. When you type a URL, your computer first checks its local cache, then queries a Recursive Resolver (typically your ISP's), which then queries Root Servers (13 clusters), then TLD servers (.com, .org), then Authoritative Name Servers for the specific domain. The result is cached for a duration set by the TTL (Time to Live). DNS records include: A (IPv4 address), AAAA (IPv6), CNAME (alias), MX (mail server), TXT (text, used for SPF, DKIM), NS (name server).