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DNS

Domain Name System

Portrait of Robert Klimant, co-founder of Roelu Studio
Robert KlimantCo-founder

What is DNS?

DNS is the internet's address-resolution layer, short for Domain Name System. It translates human-readable domain names like roelu.com into IP addresses like 192.0.2.1 — the numeric labels servers use to communicate with each other. Every time you visit a site, send an email, or load an API, DNS quietly resolves the name to a destination in milliseconds. Without it, the modern internet would not function at all.

Why it matters

DNS is invisible until it breaks, and when it breaks, everything breaks at once. Your website goes dark. Your email stops. Your SaaS tools fail to load. Most outages traced back to DNS happen because a record was misconfigured, a registrar account got hijacked, or someone forgot to renew the domain. Treat DNS like production infrastructure, not a settings page. Use a fast, reliable provider like Cloudflare. Document every record. Lock the registrar account. And when migrating a site, lower TTLs before the cutover so changes propagate in minutes, not days.

How it works

When you type a domain into a browser, your device asks a DNS resolver — usually run by your ISP or a public service like 1.1.1.1 — for the IP address. The resolver checks its cache. If the answer is not there, it walks up the DNS hierarchy: root servers, then the top-level domain server for .com or .io, then the authoritative server for the domain itself. Once it has the IP, it returns the answer and the browser connects. The whole lookup typically completes in under fifty milliseconds, and the result is cached so the next request is instant.

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