HostingChecker

Glossary

DNS (Domain Name System)

DNS is the internet phone book that translates human-readable domain names like example.com into the IP addresses computers use to connect.

The DNS (Domain Name System) is the distributed directory that maps human-friendly domain names to machine-usable IP addresses. When you type example.com, DNS resolves it to an ip-address so your browser knows where to connect.

How a lookup works

  1. Your resolver asks the root servers where to find .com.
  2. The .com TLD servers point to the domain's authoritative nameserver.
  3. The nameserver returns the requested record — an a-record, aaaa-record, mx-record, and so on.
  4. The answer is cached for the duration of its ttl.

Record types you will meet

  • a-record / aaaa-record — names to IPv4/IPv6 addresses.
  • cname-record — an alias to another name.
  • mx-record — mail routing.
  • txt-record — verification and policy strings.

Why it matters for hosting

DNS controls where your domain points, how fast changes propagate (ttl), and — with dnssec — whether answers can be trusted. Migrating hosting almost always means editing DNS records.

See also

A Record An A record is the DNS entry that maps a domain name to an IPv4 address, telling browsers exactly which server hosts the website. MX Record An MX record is the DNS entry that directs a domain’s email to the correct mail servers, with priority values choosing primary and backups. Nameserver A nameserver is a server that answers DNS queries for a domain, storing its zone records and telling the internet where the domain points. TTL (Time To Live) TTL is the number of seconds a DNS record may be cached before resolvers must fetch a fresh copy, controlling how fast changes propagate. DNSSEC DNSSEC adds cryptographic signatures to DNS records so resolvers can verify answers are authentic and have not been forged or tampered with.
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