What is DNS?

DNS (Domain Name System) translates human-readable domain names (like example.com) into IP addresses that servers understand. Think of it as the internet's phone book.

Record Types Explained

A Record

Points a domain or subdomain to an IPv4 address.
  • example.com → 123.45.67.89
  • blog.example.com → 123.45.67.89

AAAA Record

Same as A record but for IPv6 addresses.
  • example.com → 2001:db8::1

CNAME Record

Creates an alias for another domain name. Cannot be used on the root domain.
  • www.example.com → example.com

MX Record

Specifies the mail server for the domain. Has a priority number (lower = higher priority).
  • example.com → 10 mail.example.com

TXT Record

Holds text data. Used for email authentication (SPF, DKIM, DMARC) and domain verification.
  • example.com → v=spf1 a mx ~all

NS Record

Specifies the nameservers for the domain.

SRV Record

Specifies a server for a specific service (used by some apps like Microsoft 365).

TTL (Time to Live)

TTL tells DNS resolvers how long to cache a record. Common values:

  • 300 (5 minutes) — Good for records you change often
  • 3600 (1 hour) — Standard default
  • 86400 (24 hours) — For records that rarely change