Domain Name System (DNS) — the internet’s address book.

What is DNS and Why It’s Important?

Have you ever wondered how your browser knows where to go when you type something like google.com? You can thank the Domain Name System (DNS) — the internet’s address book.

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🧭 What is DNS?

DNS (Domain Name System) translates human-friendly domain names like example.com into IP addresses like 93.184.216.34 that computers use to identify each other.

Without DNS, you'd need to memorize numeric IPs for every website. Imagine typing 142.250.190.78 instead of youtube.com!

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Types of DNS Records You Should Know

DNS records are entries in the DNS database. Here are the most common types:

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DNS Hierarchy Explained: From Root to Authoritative Servers

DNS follows a hierarchical structure, working step-by-step to resolve a domain name:

1. Root DNS Server (.)

   • Knows where the top-level domains (TLDs) like .com, .org, .net are.

2. TLD Server

   • Points to name servers for the specific domain (example.com).

3. Authoritative DNS Server

   • Holds the actual IP address for www.example.com.

🧾 Example Lookup: www.example.com

1. User types www.example.com

2. OS checks local DNS cache

3. If not found, asks the Recursive Resolver

4. Resolver asks Root Server

5. Root points to .com TLD Server

6. TLD points to Authoritative Server for example.com

7. Authoritative Server returns the IP address

8. Browser loads the website!