What is DNS?

DNS (Domain Name System) is the internet's phone book. It translates human-readable domain names like "example.com" into IP addresses (like 93.184.216.34) that computers use to locate and communicate with web servers.

What is DNS (Domain Name System)?

The Domain Name System (DNS) is a hierarchical, distributed naming system that acts as the internet's address book. It translates domain names that humans can read and remember — like myphphosting.com — into the numerical IP addresses that computers use to identify and communicate with each other.

How DNS Works: Step by Step

  1. You type example.com into your browser.
  2. Your device checks its local cache. If it has recently looked up this domain, it uses the cached result.
  3. If not cached, your device queries a DNS resolver (usually provided by your ISP or a public resolver like Google's 8.8.8.8 or Cloudflare's 1.1.1.1).
  4. The resolver queries the root name servers → TLD name servers (.com) → authoritative name servers for example.com.
  5. The authoritative name server returns the IP address (e.g., 93.184.216.34).
  6. Your browser connects to that IP address and loads the website.

Common DNS Record Types

  • A record — Maps a domain to an IPv4 address (e.g., example.com → 93.184.216.34).
  • AAAA record — Maps a domain to an IPv6 address.
  • CNAME record — Creates an alias pointing one domain to another (e.g., www.example.com → example.com).
  • MX record — Specifies mail servers for a domain (used for email routing).
  • TXT record — Stores text data, used for domain verification and SPF/DKIM email authentication.
  • NS record — Specifies which name servers are authoritative for the domain.

DNS Propagation

When you change DNS records — for example, when you move your website to a new host — the change doesn't take effect instantly worldwide. DNS changes can take 24–48 hours to propagate globally because DNS records are cached at each level with a Time-To-Live (TTL) value. Setting a low TTL before a planned migration speeds up propagation.