What is DNS and the DNS Hierarchy?

Every time you type google.com into your browser, a powerful system works behind the scenes to connect you to the correct website. That system is called DNS — Domain Name System.Let’s explore what DNS does, how it works, and why it’s essential for your website — in the simplest terms, using Google as an example.

What is DNS?

DNS is the internet’s address book. It translates domain names like google.com or ava.hosting into IP addresses like 142.250.187.206, which are used by servers and routers to find each other.Without DNS, you’d have to remember IP numbers for every site you visit. Thanks to DNS, you can just use names.

 How DNS Works (Using Google.com as an Example)

Here’s what really happens when you type google.com in your browser:

• You hit Enter in your browser.
• Your computer asks: “What’s the IP address of google.com?”
• If it’s not already stored (cached), the DNS resolver sends the question into the DNS system.
• It climbs through the DNS hierarchy to find the correct IP address.
• Once found, your browser connects to that IP — and the Google homepage appears.

All of this takes milliseconds.

 Understanding the DNS Hierarchy — Step-by-Step

DNS is a global distributed system. It’s structured in layers, each playing a specific role:

1. Root DNS Servers (.)

The top of the hierarchy. They don’t know google.com, but they know where to find .com.

2. TLD Name Servers (.com)

These servers handle top-level domains like .com, .net, .md, etc. They respond:

“For google.com, check with its authoritative nameservers.”

3. Authoritative Name Servers

These are the final source of truth for a domain. For google.com, it could be ns1.google.com, etc. They reply with the exact IP address:

“google.com → 142.250.187.206”

4. Your Device (Resolver)

The final IP is returned to your device and saved in cache — so future visits are instant.

 What is DNS Caching?

Caching stores DNS results temporarily so repeat lookups are fast:

• Browser cache – remembers recently visited domains.
• OS cache – your computer stores records.
• ISP/public DNS cache – like 8.8.8.8 from Google.

If a site changes IP but your cache is outdated, you may see errors — flushing DNS often resolves that.

 Common DNS Record Types (With Examples)

 Domain Registration with AvaHost

When you register a domain through AvaHost, you gain full control over DNS zone management via an intuitive dashboard.

•  Set and update A, CNAME, MX, TXT, and SPF records
•  Point domains to VPS, dedicated servers, or external services
•  Manage email and subdomain routing
•  Integrate with external CDNs or DNS providers like Cloudflare

Whether you host with AvaHost or elsewhere, your DNS zone remains under your control — with lightning-fast propagation.

 Where Can You Check DNS?

To check DNS records, propagation status, or troubleshoot issues, you can use:

• 🔎 https://dnschecker.org — check DNS propagation globally
• 🔎 nslookup or dig tools — for command-line users
• 🔎 WHOIS & DNS sections on domain registrar dashboards

These tools help verify if your domain is resolving correctly or if records are misconfigured.

 Conclusion

DNS is the invisible system that powers everything online. It turns names into directions, and it keeps your site reachable from anywhere in the world.Now that you understand how google.com gets resolved, you’re ready to manage your own domains and hosting with more confidence.