What's a Domain Name and What's Behind the Scene

I've worked with domain names for over 15 years — registering them, managing DNS zones, building products around them. This article explains how they work from first principles: what they are, who manages them, and what happens every time you type a URL into your browser.

Glowing blue network cables connected to server switches in a data center

What Is a Domain Name?

A domain name is a human-readable address for an internet resource. Instead of remembering 93.184.216.34, you remember example.com. That's the entire point — humans are terrible at remembering numbers.

Domain names have structure. Take www.example.com:

  • .com — the Top-Level Domain (TLD)
  • example — the second-level domain (the part you register)
  • www — a subdomain (optional, configured by the domain owner)

TLDs: The Top of the Tree

Top-Level Domains are managed by ICANN (Internet Corporation for Assigned Names and Numbers). The main types:

  • Generic TLDs (gTLDs): .com, .net, .org, .info, and hundreds of newer ones like .tech, .shop, .app
  • Country-code TLDs (ccTLDs): .lu (Luxembourg), .fr (France), .uk (United Kingdom), .de (Germany)
  • Sponsored TLDs: .edu, .gov, .mil — restricted to specific communities

Each TLD is operated by a registry. Verisign operates .com and .net. The registry maintains the master database of all domains under that TLD.

Registrars: Where You Buy Domains

You don't buy from the registry directly. You go through a registrar — a company accredited by ICANN (or by a ccTLD registry) to sell domain names.

When you "buy" a domain, you're registering the right to use it for a period (usually 1–10 years). The registrar communicates with the registry via EPP (Extensible Provisioning Protocol) to create, renew, transfer, and update registrations.

Having spent years at EuroDNS — one of Europe's major registrars — I can tell you the EPP layer is where most of the complexity lives. It's also where most things break during transfers and migrations.

WHOIS: Who Owns What

Every domain registration includes contact information in the WHOIS database. Query it to find the registrant, creation date, expiry, and nameservers.

whois example.com

With GDPR, many registrars now offer WHOIS privacy protection, masking personal data. This was a massive shift — especially in Europe, where we had to rethink how domain ownership transparency works.

The DNS Resolution Chain

When you type example.com in your browser, a chain of lookups happens in milliseconds:

Step 1: Local Cache

Your OS checks its local DNS cache. If you've visited recently, the answer is already there.

Step 2: Recursive Resolver

If not cached, your computer asks a recursive resolver — typically your ISP's, or a public one like Google (8.8.8.8) or Cloudflare (1.1.1.1). This server does the heavy lifting.

Step 3: Root Servers

The resolver starts at the top: one of the 13 root server clusters. "Where do I find .com?" The root responds with the .com TLD nameservers.

Step 4: TLD Nameservers

The resolver asks the .com nameserver: "Where's example.com?" It responds with the domain's authoritative nameservers.

Step 5: Authoritative Nameserver

The resolver asks the authoritative server: "What's the IP for example.com?" This server holds the actual records and returns the answer.

Step 6: Response

The resolver caches the result (based on TTL) and sends it to your browser. Connection established.

This entire chain completes in milliseconds. Billions of times per day. Most people have no idea it's happening.

TTL: How Long to Remember

Every DNS record has a TTL (Time to Live) in seconds. It tells resolvers how long to cache the answer.

  • 300 (5 minutes) — records that change frequently
  • 3600 (1 hour) — a solid default
  • 86400 (24 hours) — stable records

Pro tip: Before making DNS changes, lower the TTL well in advance. I drop it 24–48 hours before the change, make the switch, then raise it back. Saves you from staring at stale caches.

Nameservers: The Source of Truth

Nameservers host your DNS zone — the file containing all your records (A, AAAA, MX, CNAME, TXT, etc.). When you register a domain, one of the first things you configure is which nameservers are authoritative for it.

You can use your registrar's nameservers, your hosting provider's, or run your own. The nameserver information lives at the registry level, so the resolution chain knows where to find your records.

The Bigger Picture

DNS is one of the most elegant systems ever built. A distributed, hierarchical database that translates human-friendly names into machine addresses — billions of times daily, in milliseconds, worldwide.

If you work anywhere near internet infrastructure, understanding DNS isn't optional. Everything starts with a name.