Understanding DNS: How the Internet Finds What You Need

If you've ever wondered how typing a website name leads you to the right page, the Domain Name System (DNS) is the answer. Instead of memorizing long, complicated IP addresses, DNS acts as the internet’s phonebook, translating human-friendly domain names into machine-readable addresses.

Breaking Down the Domain Hierarchy

DNS is structured in a hierarchy, starting from the root domain, which is represented by a dot (.), followed by top-level domains (TLDs) like .com, .org, or .net. Beneath these are second-level domains, which are the names we commonly recognize—like example.com.

Key DNS Record Types

DNS records help route internet traffic efficiently. Some essential record types include:

• A Record: Maps a domain to an IPv4 address.
• AAAA Record: Similar to an A record but for IPv6 addresses.
• CNAME Record: Redirects one domain to another (e.g., www.example.com to example.com).
• MX Record: Directs email to the correct mail servers.
• TXT Record: Stores arbitrary text, often used for security and verification purposes.

What Happens When You Make a DNS Request?

Whenever you type a URL into your browser, a DNS lookup occurs. Your computer contacts a recursive resolver, which queries different DNS servers to find the correct IP address. Once the address is retrieved, your browser connects to the website’s server, loading the page you requested.

Hands-On DNS Queries

To solidify my understanding, I practiced making DNS queries myself, observing how different records work in real-world applications.

Next up in my learning journey: diving into HTTP in Detail to explore how web requests and responses function! Stay tuned.