Cloud & DevOps

What is Domain Name System?

Quick answer

The internet's directory service that translates human-friendly domain names into the numeric IP addresses computers use.

Domain Name System, explained

When you type a web address into a browser, your device asks a DNS resolver which IP address belongs to that name. The resolver works through a hierarchy of servers, from the root servers to top-level domain servers such as those for .com, and finally to the domain's authoritative name server, then returns the answer.

DNS records serve different purposes: A and AAAA records point to IPv4 and IPv6 addresses, CNAME records create aliases, and MX records direct email. Answers are cached to speed up repeat lookups. Because DNS is so fundamental, outages or misconfigurations can take websites offline, and attackers target it through techniques like DNS spoofing. Extensions such as DNSSEC and DNS over HTTPS add security and privacy.

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