Websites and Tech

Domain Name System (DNS)

Also called DNS, nameservers

The address book of the internet, translating a domain name into the server address a browser needs.

Quick facts: Domain Name System (DNS)

Category
Websites and Tech
Also called
DNS, nameservers
Level
Intermediate
Affects
Website availability, email delivery, platform verifications, migrations
Where to see it
Your registrar's control panel, hosting DNS manager, Cloudflare, Google Search Console
In this article4
  1. How DNS works
  2. Why DNS matters
  3. Common mistakes with DNS
  4. How to act on it

How DNS works

People remember names; machines need numbers. When someone types your domain, their device asks the domain name system where that name currently lives, receives a server address, and connects to it. The whole exchange happens before your site does anything at all, which is why a domain problem looks like a dead website even when the server is perfectly healthy.

Your domain points at a set of nameservers, and those nameservers hold the records that answer each type of question. A handful do most of the work:

  • A record — the server address the website itself is served from.
  • CNAME — an alias that says one name should follow another, often used for subdomains and third-party services.
  • MX — where email for the domain should be delivered.
  • TXT — free text used to prove ownership and to publish email authentication rules.

Each record carries a time to live, which tells everyone else how long they may remember the answer before asking again. That is why a change is not instant: the old answer is still cached in places you do not control until it expires.

Why DNS matters

Three things you depend on run through it and can be broken independently of each other: your website, your email and your verifications. Moving a site to new hosting without touching mail records is routine; changing nameservers carelessly and taking the company email down with the site is equally routine, and far more painful.

It is also where ownership lives. Whoever controls the domain registration controls where the name points, regardless of who built the site or who pays the hosting bill. Businesses discover this at the worst possible moment, when a former agency or a departed staff member holds the only login.

Common mistakes with DNS

The first is not knowing where the records are edited. A domain can be registered in one place, have its nameservers hosted in a second, and serve the website from a third; changes made in the wrong dashboard have no effect and people conclude the change did not work.

The second is deleting text records that look like clutter. Those strings are often what verify your domain with Search Console, an ad platform or your email provider, and removing them quietly withdraws access or damages email delivery. The third is letting the registration lapse. A domain that expires does not politely wait for you; the site, the email and the search visibility built on it all stop at once.

How to act on it

Keep the domain registered in the business’s own account, with auto-renewal on, the transfer lock enabled and recovery details someone still working there can reach. Before any migration, export or screenshot the current records so you can restore them exactly, and lower the time to live in advance so the switch takes effect quickly when you make it.

Change one thing at a time and check email as well as the website afterwards, including a test message from outside the company. If a site move is involved, plan it as a proper hosting migration with the new server tested before the name is pointed at it, and keep the old one running until traffic has settled. Treat email authentication records as part of the same job rather than something to fix afterwards.

Do and do not

Do

  • Register the domain in the business's own account
  • Export the current records before any migration
  • Lower the time to live before a planned switch

Do not

  • Delete text records you cannot immediately explain
  • Change nameservers without copying the mail records
  • Let the registration renew through a personal card only

Questions people ask about this

Why hasn't my DNS change taken effect yet?

Because the previous answer is still remembered elsewhere. Every record carries a time to live that tells networks and devices how long they may reuse the old value before asking again, and that clock started before you made the change. Lowering the time to live in advance of a planned move shortens the wait considerably.

Will changing hosting break my email?

It will if you move the nameservers without recreating the mail records at the new provider. Website records and mail records are separate, so copy the existing MX and text records first, then verify that a message sent from outside the company still arrives. Doing this before the switch, rather than after, avoids losing enquiries.

Who should own my domain name?

The business, in an account the business controls, with billing and recovery details that survive staff changes. Agencies and developers often register domains as a convenience, and that is fine until the relationship ends. Check the registrar login yourself, enable auto-renewal, and keep the transfer lock on so nobody can move the name without your consent.

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