DNS, or Domain Name System, is the service that translates human-readable domain names into IP addresses that computers use to communicate. Instead of memorizing numeric addresses, users type names like example.com, and DNS resolves them to server locations. DNS consists of hierarchical servers, including root servers, TLD servers, and authoritative name servers. Each domain uses records such as A, AAAA, CNAME, and TXT to define how traffic should be routed.
Why it matters
Without DNS, the internet would be far less usable and more error-prone. Understanding DNS helps diagnose issues like unreachable websites, misconfigured email services, and SSL errors. It is also essential for deploying applications and setting up custom domains.
Examples
Setting an A record to point example.com to a server’s IP or configuring a CNAME for www are common DNS tasks. DNS concepts are covered in lessons like What Is DNS? and How DNS Lookups Work.