Getting Started with DNS: The Internet's Address Book

What is DNS?

Welcome to our DNS series! Before diving into the technical details, let’s start with a simple question: What is DNS?

Imagine your phone’s contact list. You don’t need to memorize every friend’s phone number—just their names. When you want to call “Zhang San,” you find the name in your contacts and tap to dial. Your phone automatically looks up Zhang San’s phone number and places the call.

DNS (Domain Name System) plays a similar role as the “contact list of the Internet.” It takes the human-friendly domain names we remember—like www.google.com—and translates them into the IP addresses computers understand, such as 172.217.160.78. Without DNS, we’d have to memorize long, random strings of numbers to visit websites, which would be nearly impossible.

How Does DNS Work?

This “translation” happens behind the scenes in the blink of an eye. When you type a web address in your browser, the process roughly follows these steps:

1. Request: Your computer or phone sends a request to a DNS resolver: “What’s the IP address of www.example.com?”
2. Query: Like a detective, the resolver performs a series of lookups—from the root servers, to the top-level-domain servers, to the authoritative name servers—to find the answer.
3. Response: Once it has the answer, the resolver returns the IP address to your computer.
4. Connection: Your browser uses this IP address to connect to the website’s server and display the web page in front of you.

What Will We Cover in This Series?

The world of DNS is far richer and more complex than this simple analogy suggests. In this series we’ll take you through everything DNS has to offer:

• Core Concepts: Understand in depth what domain names, IP addresses, and the relationship between them truly are.
• Record Types: Learn the purpose of different DNS records—A, CNAME, MX, and more.
• Server Types: Discover the distinct roles played by recursive servers, authoritative servers, and others.
• DNS Lookup Process: Break down every step of a full DNS query in detail.
• DNS Caching: See how DNS caching speeds up website access.
• Private DNS: How to set up and use a private DNS service to enhance security and privacy on your network.

Whether you’re brand-new to networking or a developer who wants to solidify the fundamentals, this series will provide clear, easy-to-follow guidance.

Let’s begin our journey into DNS!