// Learn

What is DNS?

DNS (Domain Name System) is the phone book of the internet. It translates human-readable domain names into the IP addresses computers use to find each other.

The short version

When you type 1t3r8.dev into your browser, your computer doesn't know where that is. It asks a DNS server, which looks up the domain name and returns an IP address like 76.76.21.21. Your browser then connects to that address. This happens in milliseconds, before the page even starts loading.

Every website, every API, every service on the internet relies on DNS. It's invisible when it works and catastrophic when it breaks.

How it works

DNS is a hierarchy of lookups:

  • Domain registrar is where you buy the domain name (Cloudflare, Namecheap, Google Domains). You own the name, and you tell the registrar which DNS servers are authoritative for it.
  • DNS records are the actual entries that map names to addresses. The main types:
    • A record: maps a domain to an IPv4 address. 1t3r8.dev → 76.76.21.21
    • CNAME record: maps one domain to another. www.1t3r8.dev → 1t3r8.dev
    • MX record: tells email where to go. 1t3r8.dev → mail.protonmail.ch
    • TXT record: holds text data, often used for verification ("prove you own this domain")
  • TTL (Time To Live) is how long other servers cache the answer. A TTL of 300 means the record is cached for 5 minutes before being looked up again.

When you change a DNS record, the change doesn't take effect instantly. Old cached answers have to expire first. This is DNS propagation, and it can take minutes to hours depending on TTL values.

Why it matters

If you've ever set up a custom domain for a website, connected an email service, or pointed a domain at Vercel or Cloudflare, you've edited DNS records. Understanding what A records, CNAMEs, and TTLs do means you can debug "my domain isn't working" problems yourself instead of waiting for support.

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//Read more

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