Every time you type a website address into your browser, something invisible happens before the page loads: your computer has to turn that human-friendly name into an IP address. That translation is the job of the Domain Name System, or DNS — often called the phonebook of the internet.

Here is the short version of what happens when you visit a site:

  1. Your browser checks its own cache, then asks your operating system's resolver.
  2. The resolver asks a recursive DNS server (usually run by your ISP or a public provider like Cloudflare or Google).
  3. That server walks the DNS hierarchy: it asks a root server where to find the top-level domain (like .com), then asks the TLD server where the domain's authoritative nameserver lives, then asks that nameserver for the actual A or AAAA record.
  4. The answer — an IP address — comes back, gets cached for a while, and your browser connects.

A few things worth knowing:

  • Caching happens at every step, which is why DNS changes can take time to show up everywhere.
  • If any link in that chain is slow or wrong, you get the classic "site can't be reached" even though the site itself is fine.
  • You can watch this process yourself with a DNS lookup tool, which shows exactly which records a domain publishes.

If you want the fuller walkthrough, with examples of each record type and how to check them yourself, I wrote it up here: https://trustmyip.com/blog/how-dns-resolves-domain-names-to-ips

DNS is one of those things that just works until it doesn't — and when it doesn't, knowing how the lookup chain works makes troubleshooting ten times faster.