How the Domain Name System (DNS) Works
Understanding the DNS Infrastructure
Computers communicate using numbers called IP addresses (like 142.250.190.46). However, humans are terrible at remembering long lists of numbers. The Domain Name System (DNS) was created to solve this by mapping human-friendly names (like google.com) to these IP addresses. Think of DNS as the phonebook of the internet.
The Step-by-Step DNS Resolution Process
When you type a domain name into your browser, a complex request chain happens behind the scenes in milliseconds:
- The Request: Your browser asks your router, which queries a DNS Resolver (usually run by your ISP or a public service like Cloudflare's 1.1.1.1).
- Root Servers: The resolver queries a Root Name Server to find who handles the Top-Level Domain (e.g., .com).
- TLD Servers: The root server points to the TLD Name Server, which holds data for all domains under that extension.
- Authoritative Nameservers: The TLD server points to your registrar's or host's Nameservers (like
ns1.hostinger.com). - The IP Resolution: Your nameservers look at the active DNS zone file (like the A Record) and return the destination server's IP address to your browser.
Key DNS Record Types to Know
- A Record (Address): Directs your domain name to an IPv4 hosting server.
- AAAA Record: Directs your domain name to an IPv6 hosting server.
- CNAME (Canonical Name): Points a subdomain (like
www.yourdomain.com) to another domain name. - MX Record (Mail Exchange): Routes email traffic to the correct mail server (like Google Workspace).
- TXT Record (Text): Used for ownership verification and email security records (SPF, DKIM).