The Domain Name System is the distributed database that translates human-readable domain names (crashbytes.com) into the IP addresses that networks actually route to. DNS is implemented as a global hierarchical system of servers — root servers at the top, TLD servers (.com, .org) below them, authoritative servers for each domain below those, and caching resolvers throughout.
DNS is typically invisible to users until it breaks. Major DNS outages tend to produce cascading internet-wide failures because almost every networked service depends on DNS resolution somewhere in its request path. Cloudflare, AWS Route 53, and Google Cloud DNS are the largest commercial DNS providers, though every major ISP also runs its own resolvers.
Security-focused DNS variants — DNS over HTTPS (DoH), DNS over TLS (DoT), DNSSEC — have gained adoption in response to both privacy concerns and DNS-based attacks. As of 2026, DoH is the default on major browsers and mobile operating systems, which has substantially changed the DNS privacy landscape relative to the unencrypted legacy protocol.